Gooey and loaded with fun, these Funfetti Bars start with a chocolate chip cookie base topped with marshmallows, M&M’s, chocolate pretzels, and sprinkles—sweet, crunchy, and irresistible!
Preheat oven to 325°F. Line an 8x8-inch pan with parchment paper (do not skip—these bars are sticky!) and set aside.
In a large bowl, using a hand mixer, cream the room-temperature butter (not melted) with the brown sugar and granulated sugar. Beat in the egg and vanilla extract. Add baking soda, salt, flour, and chocolate chips. Beat until the dough is combined and smooth. It will be a bit wet.
Press the dough evenly into the bottom of the prepared pan and bake for 19–23 minutes or until lightly golden brown at the edges and firm in the center (shouldn’t be glossy).
Remove from the oven and top with the marshmallows. Bake for 1 and 1/2 more minutes and remove from the oven to a cooling rack.
Top with the mini M&M’s, coarsely chopped chocolate pretzels, and sprinkles.
Let Funfetti Bars cool at room temperature for at least an hour, then cut into bars (with a hot sharp knife—run under hot water, dry, cut, repeat), and enjoy. These are best enjoyed within the same day because of the marshmallows.
Notes
Note 1: Mini M&M’s can be found in the baking aisle of most grocery stores; they’re labeled as M&M milk chocolate baking bits.Storage: If you have leftovers, you can keep these bars, tightly covered, at room temperature for up to 3 days. They can also be stored in an airtight container in the fridge for up to a week, but the marshmallow does lose flavor and texture.