Salted Caramel Apple Marshmallow Squares with Streusel
Apple Marshmallow
Chewy marshmallow bars with tart apple, caramel swirls, and cinnamon streusel.
Nutrition (per serving)
These Salted Caramel Apple Marshmallow Squares are a cozy, slightly nostalgic dessert that marries tart baked apples with pillowy marshmallow and sticky caramel, all finished with a buttery cinnamon streusel. They cut into cheerful squares that are perfect for sharing at a weekend brunch or bringing to a potluck.
I love how the textures play together—the crunch of streusel, the soft chew of marshmallow, and juicy apple pockets—plus the little flip of salt on top brightens all the flavors. Serve warm with coffee or a scoop of vanilla ice cream for maximum comfort.
Ingredients
- Graham cracker crumbs:2 cups
- Unsalted butter (melted, for crust):6 tbsp
- Granulated sugar (for crust):2 tbsp
- Granny Smith apples (peeled, cored, diced):2 pieces
- Unsalted butter (for apples):1 tbsp
- Brown sugar (for apples):1/4 cup
- Ground cinnamon:1 tsp
- Lemon juice:1 tbsp
- Vanilla extract:1 tsp
- Mini marshmallows:3 cups
- Caramel sauce:3/4 cup
- All-purpose flour (streusel):1/2 cup
- Rolled oats (streusel):1/2 cup
- Brown sugar (streusel):1/3 cup
- Cold unsalted butter (cubed, streusel):6 tbsp
- Kosher salt:1/4 tsp
- Flaky sea salt (finish):1/4 tsp
- Chopped pecans (optional):1/3 cup
Instructions
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Preheat the oven to 350°F. Line a 9x13-inch pan with parchment, leaving an overhang for easy removal.
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Make the crust: combine graham cracker crumbs, melted butter, and 2 tbsp granulated sugar in a bowl. Press firmly into the bottom of the prepared pan and bake 8 minutes; remove and set aside.
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Prepare the apples: heat 1 tbsp butter in a skillet over medium. Add diced apples, 1/4 cup brown sugar, 1 tsp cinnamon, and 1 tbsp lemon juice. Cook until apples are tender and syrupy, about 6–8 minutes. Stir in 1 tsp vanilla and cool slightly.
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Spread the cooked apples evenly over the warmed crust in the pan.
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Scatter the mini marshmallows evenly over the apples, then spoon the caramel sauce in dollops across the marshmallows. Gently press a few dollops so caramel peeks through the marshmallow layer.
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Make the streusel: in a bowl combine 1/2 cup flour, 1/2 cup oats, 1/3 cup brown sugar, and 1/4 tsp kosher salt. Cut in the 6 tbsp cold cubed butter with a pastry cutter or fingers until coarse crumbs form. Stir in chopped pecans if using.
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Sprinkle the streusel evenly over the marshmallow and caramel layer.
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Bake in the 350°F oven until the streusel is golden and marshmallows have puffed slightly, 12–15 minutes. If you like a browned marshmallow top, broil 30–45 seconds while watching closely.
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Remove from oven and let cool at least 20 minutes in the pan to set. Finish with a light sprinkle of flaky sea salt and, if desired, an extra drizzle of warm caramel.
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Lift the bars from the pan using the parchment overhang and cut into 12 squares. Serve warm or at room temperature.
Tips & Notes
- For easiest slicing, chill the pan briefly after cooling so the marshmallow firms up—dip your knife in hot water and wipe between cuts.
- Use tart apples like Granny Smith to balance the sweetness; softer apples will turn silkier but may release more moisture.
- Store leftovers in an airtight container at room temperature for up to 2 days or refrigerate up to 5 days; rewarm briefly in the oven before serving.
- Swap pecans for walnuts or omit nuts entirely for a nut-free treat.
