Smores Oatmeal Crumble Bars
Craving the perfect blend of cozy comfort and indulgent sweetness? These S’mores Oatmeal Crumble Bars are the answer! With layers of toasted oats, gooey marshmallows, rich chocolate, and a hint of graham cracker crunch, this dessert brings all the classic flavors of a campfire favorite into an irresistible bar form. Whether you’re baking for a family treat or a crowd-pleasing snack, these bars are sure to become a go-to recipe for any occasion.

Reasons Why You’ll Love This Recipe
- Easy to make: No need for an open fire—this recipe gives you all the s’mores fun without the hassle.
- Oatmeal added texture: The hearty oatmeal crumble provides a chewy, satisfying texture that contrasts beautifully with the gooey filling.
- Family-friendly: A fun and delicious treat that both kids and adults will love.
- Make ahead: Perfect for prepping in advance—store them in an airtight container for a quick snack or dessert whenever you need it.
- S’mores nostalgia: Enjoy all the nostalgic campfire feels, no matter the season or weather!

Ingredients You’ll Need For These Smores Oatmeal Crumble Bars
- Butter: Adds richness and moisture to the crumble topping and helps bind the ingredients for the crust together.
- Graham Crackers: These provide the iconic graham cracker crust flavor and a touch of crunch that mimics the classic s’mores experience.
- Brown Sugar: Sweetens the bars with a rich, molasses-like flavor that enhances the oatmeal and graham cracker layers.
- Semi-Sweet Chocolate: Melts into gooey, indulgent pockets of chocolate throughout the bars, adding that essential s’mores flavor.
- Sweetened Condensed Milk: Provides a creamy, slightly caramelized sweetness that helps bind the filling and gives it a rich texture.
- Vanilla: Enhances the sweetness and flavor profile of the bars, giving a warm, comforting taste.
- Mini Marshmallows: These are the star of the show, creating gooey, melty pockets of marshmallow goodness that make these bars irresistible.
- Oats: The heart of the crumble, adding chewiness and a satisfying texture to balance out the sweetness.
- Flour: Works with the oats and butter to create a sturdy, crumbly base that holds everything together.
- Cinnamon: Adds a warm, spiced note that complements the sweetness of the marshmallows and chocolate.
- Salt: A pinch of salt enhances the sweetness and helps to balance out the rich flavors, bringing all the ingredients together.
How to Make This Recipe
Start by making the graham cracker crust. In a food processor, combine crushed graham crackers, melted butter, and brown sugar. Mix everything together until the mixture is well-combined and resembles wet sand. Press this mixture into the bottom of a greased baking dish to form an even layer.


Next, prepare the chocolate middle. In a microwave-safe bowl, combine the semi-sweet chocolate, sweetened condensed milk, butter, and vanilla. Microwave the mixture in 30-second intervals, stirring between each, until everything is fully melted and smooth.
Once the chocolate mixture is ready, pour it over the graham cracker crust and spread it evenly. Refrigerate the bars for at least 3 hours to allow the chocolate to set and firm up.


After the chocolate has chilled, top the bars with mini marshmallows, spreading them evenly across the surface. Now, make the oat crumble by combining oats, flour, brown sugar, cinnamon, salt, and melted butter in a bowl.
Mix until the crumble is evenly coated and forms small clumps. Sprinkle this oat crumble mixture evenly over the marshmallows & adding more mini marshmallows on top.


Place the baking dish under the broiler for 2-3 minutes, keeping a close eye on it, until the marshmallows are golden and the oat crumble is slightly toasted. Remove from the oven, let the bars cool, and then refrigerate again if needed. Slice into bars and enjoy this gooey, decadent treat!

Storage Tips For This Recipe
- Room Temperature: Store the bars in an airtight container at room temperature for up to 2-3 days. This will keep them fresh and soft, with the marshmallows retaining their gooey texture.
- Refrigeration: If you want to extend the shelf life, refrigerate the bars in an airtight container for up to 1 week. Chilling them also helps keep the chocolate and marshmallow layers firm.
- Freezing: For longer storage, these bars freeze beautifully. Wrap individual bars tightly in plastic wrap or foil, then place them in a freezer-safe container or zip-top bag. They can be stored in the freezer for up to 2-3 months. To thaw, let them sit at room temperature for 20-30 minutes or microwave them for a few seconds.
- Preventing Sticky Marshmallows: If you’re storing the bars with marshmallows on top, it’s helpful to place a sheet of parchment paper between layers of bars in the container to prevent the marshmallows from sticking to each other.
Common FAQ’s Related to This Recipe
- Can I use a different type of chocolate?
Yes! You can swap the semi-sweet chocolate for milk chocolate, dark chocolate, or white chocolate, depending on your preference. - Can I use a different type of sugar in the crumble topping?
You can substitute brown sugar with white sugar, although brown sugar adds a richer flavor. Other sweeteners like coconut sugar may alter the texture slightly. - Can I freeze these bars?
Yes, wrap the bars individually in plastic wrap or foil and store in a freezer-safe container for up to 2-3 months. Thaw at room temperature or microwave to enjoy later. - What’s the best way to cut the bars after chilling?
Use a sharp knife dipped in hot water before each slice. Wipe the knife after each cut to maintain clean edges, especially with marshmallows on top. - Can I use regular marshmallows instead of mini marshmallows?
Yes! You can use regular-sized marshmallows, but cut them in half or quarters to help them spread more evenly. Mini marshmallows are preferred for even melting and distribution.

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Smores Oatmeal Crumble Bars
Equipment
- 9X13 Baking Dish
Ingredients
For The Crust
- 1 stick Butter melted
- 2 sleeves Graham Crackers
- 1/3 cup Brown Sugar
For The Chocolate Middle
- 3 cup Semi-Sweet Chocolate melted
- 14 oz Sweetened Condensed Milk
- 3 tbsp. Butter melted
- 1 tsp. Vanilla Extract
For The Oatmeal Crumble
- 2 cups Mini Marshmellows split in half
- 1 cup Oats
- 3/4 cup Flour
- 3/4 cup Brown Sugar
- 1/2 tsp. Cinnamon
- 1/2 tsp. Salt
- 5 tbsp. Butter melted
Instructions
For The Crust
- In a food processor, combine crushed graham crackers, melted butter, and brown sugar. Mix everything together until the mixture is well-combined and resembles wet sand.1 stick Butter, 2 sleeves Graham Crackers, 1/3 cup Brown Sugar
- Press this mixture into the bottom of a greased baking dish to form an even layer.
For The Chocolate Layer
- In a microwave-safe bowl, combine the semi-sweet chocolate, sweetened condensed milk, butter, and vanilla. Microwave the mixture in 30-second intervals, stirring between each, until everything is fully melted and smooth.3 cup Semi-Sweet Chocolate, 14 oz Sweetened Condensed Milk, 3 tbsp. Butter, 1 tsp. Vanilla Extract
- Once the chocolate mixture is ready, pour it over the graham cracker crust and spread it evenly. Refrigerate the bars for at least 1 hour to allow the chocolate to set and firm up.
For The Oatmeal Crumble
- After the chocolate has chilled, top the bars with 1/2 of the mini marshmallows, spreading them evenly across the surface.2 cups Mini Marshmellows
- Now, make the oat crumble by combining oats, flour, brown sugar, cinnamon, salt, and melted butter in a bowl.1 cup Oats, 3/4 cup Flour, 3/4 cup Brown Sugar, 1/2 tsp. Cinnamon, 1/2 tsp. Salt, 5 tbsp. Butter
- Mix until the crumble is evenly coated and forms small clumps. Sprinkle this oat crumble mixture evenly over the marshmallows & adding the rest of the mini marshmallows on top.2 cups Mini Marshmellows
- Place the baking dish under the broiler for 2-3 minutes, keeping a close eye on it, until the marshmallows are golden and the oat crumble is slightly toasted. Remove from the oven, let the bars cool, and then refrigerate again if needed. Slice into bars and enjoy this gooey, decadent treat!
Notes
Storage Tips For This Recipe
- Room Temperature: Store the bars in an airtight container at room temperature for up to 2-3 days. This will keep them fresh and soft, with the marshmallows retaining their gooey texture.
- Refrigeration: If you want to extend the shelf life, refrigerate the bars in an airtight container for up to 1 week. Chilling them also helps keep the chocolate and marshmallow layers firm.
- Freezing: For longer storage, these bars freeze beautifully. Wrap individual bars tightly in plastic wrap or foil, then place them in a freezer-safe container or zip-top bag. They can be stored in the freezer for up to 2-3 months. To thaw, let them sit at room temperature for 20-30 minutes or microwave them for a few seconds.
- Preventing Sticky Marshmallows: If you’re storing the bars with marshmallows on top, it’s helpful to place a sheet of parchment paper between layers of bars in the container to prevent the marshmallows from sticking to each other.
Common FAQ’s Related to This Recipe
- Can I use a different type of chocolate?
Yes! You can swap the semi-sweet chocolate for milk chocolate, dark chocolate, or white chocolate, depending on your preference. - Can I use a different type of sugar in the crumble topping?
You can substitute brown sugar with white sugar, although brown sugar adds a richer flavor. Other sweeteners like coconut sugar may alter the texture slightly. - Can I freeze these bars?
Yes, wrap the bars individually in plastic wrap or foil and store in a freezer-safe container for up to 2-3 months. Thaw at room temperature or microwave to enjoy later. - What’s the best way to cut the bars after chilling?
Use a sharp knife dipped in hot water before each slice. Wipe the knife after each cut to maintain clean edges, especially with marshmallows on top. - Can I use regular marshmallows instead of mini marshmallows?
Yes! You can use regular-sized marshmallows, but cut them in half or quarters to help them spread more evenly. Mini marshmallows are preferred for even melting and distribution.
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