These oven baked marshmallow vanilla wafer bars are the kind of pantry dessert that feels nostalgic, clever, and almost too simple to work until you pull the pan from the oven and see the gooey, golden top. Using whole vanilla wafer cookies creates a sturdy layered base with a soft bite after baking, while marshmallow cream and a few baking staples turn everything into easy dessert bars that slice neatly once cooled.
Serve these bars slightly warm or fully cooled with coffee, cold milk, or vanilla ice cream. They also fit nicely on a holiday cookie tray, a potluck dessert table, or packed into lunchbox-style treat boxes because the flavors are familiar, sweet, and crowd-pleasing without requiring any fancy ingredients.
Oven Baked 5-Ingredient Marshmallow Vanilla Wafer Bars
Servings: 16 bars
Ingredients
1 box vanilla wafer cookies, about 11 ounces
1 jar marshmallow cream, 7 ounces
1 can sweetened condensed milk, 14 ounces
1/2 cup unsalted butter, melted
1 teaspoon vanilla extract
Directions
1. Preheat the oven to 350°F and lightly grease a clear glass 9x13-inch baking dish.
2. Arrange the whole vanilla wafer cookies in an even layer across the bottom of the dish, covering as much of the surface as possible without breaking the cookies.
3. In a medium bowl, stir together the marshmallow cream, sweetened condensed milk, melted butter, and vanilla extract until the mixture is as smooth as possible.
4. Spoon and pour the marshmallow mixture over the cookies, then gently spread it so the cookies are covered from edge to edge.
5. Bake for 20 to 25 minutes, until the top looks puffed and lightly golden around the edges.
6. Let the bars cool completely before slicing into squares or rectangles for cleaner cuts. Serve as is, or slightly warm for a softer, gooier texture.
Variations & Tips
Buttery texture tip: Be sure the butter is fully melted and mixed thoroughly into the marshmallow cream mixture so the topping bakes evenly instead of forming dense patches.
Cooling for clean slices: If you want tidy dessert bars rather than a spoonable treat, let the pan cool fully and then chill it for 30 to 45 minutes before cutting.
Extra vanilla version: For a slightly deeper bakery-style flavor, increase the vanilla extract to 1 1/2 teaspoons. This small change rounds out the sweetness nicely without adding more ingredients.
Lightly toasted top: If the bars need a little more color after baking, place the dish under the broiler for 30 to 60 seconds, watching constantly so the marshmallow topping does not scorch.
Cookie layering option: For thicker bars, make two layers of whole wafers with a little marshmallow mixture between them, then finish with the remaining topping on top. This creates a more pronounced cookie-bar structure after baking.