Preheat oven to 350°F.

Line an 8”x8” baking pan with parchment paper so that the paper hangs over two of the edges by a couple of inches. Set pan aside.

Prepare the Brownies by placing the chocolate and butter in a small saucepan. Heat over low heat, stirring occasionally until fully melted. Remove from heat and let cool slightly.

Using a medium bowl, whisk together the white sugar, brown sugar, egg and vanilla until well combined. Add the melted chocolate and butter; stir until well combined.

Add the flour and salt; stir until just combined. (Tip: Take care not to overmix the batter.)

Transfer the batter into the prepared brownie pan. Spread the batter evenly. Set pan aside.

In a medium bowl, prepare the Blondies by whisking together the melted butter, brown sugar, egg and Caramel Marshmallow creamer. Add the flour, baking powder and salt; mix until just combined. Fold the mini-marshmallows into the batter.

Spread Blondie batter into the prepared pan on top of the Brownie batter.

Bake at 350°F for 33-35 minutes, or until a toothpick inserted into the center of the bars comes out mostly clean.

Allow bars to cool in pan. Lift the cooled bars out of the pan; slice into squares.