Step 1

Preheat 350°

Step 2

Spray a 9×13 baking pan lightly with cooking spray

Step 3

In a large bowl cream together butter, granulated sugar, 1 whole egg plus 2 yolks and vanilla until smooth.

Step 4

Add in flour, baking powder and salt and mix until just combined. Spread in prepared pan.

Step 5

Top with chocolate chips and mini marshmallows.

Step 6

In a clean mixing bowl with whisk attachment on your mixer, beat the 2 remaining egg whites until stiff peaks form, about 2 minutes on high.

Step 7

Fold in light brown sugar and stir until combined and there are no lumps.

Step 8

Spread on top of chocolate chips and marshmallows.

Step 9

Bake 30-35 minutes until top is golden brown.

Step 10

Allow to cool completely before cutting into squares