BOTTOM LAYER: Preheat oven to 350°.
Meanwhile, mix brown sugar and butter in a mixing bowl.
Beat for 5 minutes with an electric mixer.
Add two of the eggs, 2 ¼ tsp. vanilla extract and continue mixing with beater.
In a separate bowl, whisk 1 ½ cups plus 2 ½ tbsp. flour, baking powder, salt and nutmeg together.
Add flour mixture to the egg mixture and combine.
Spread mixture into a greased and floured 9x13” glass baking dish.
Bake at 350° for 30-35 minutes, or until the blondie has a golden top and is firm in the center of the dish.
TOP LAYER: Beat softened cream cheese, granulated sugar, lemon juice and 1 tsp. vanilla extract with an electric mixer until smooth and well mixed.
Add remaining 1 ½ tbsp. flour and mix again.
Add eggs one at a time mixing well after each addition.
Transfer half of the batter to a small mixing bowl.
To one of the bowls of batter, add cocoa powder and red food coloring.
Mix with an electric mixer until thoroughly combined.
Pour the red velvet batter mixture on top of the baked blondie.
Then pour the white cheesecake batter on top of the red velvet layer.
Using a spoon, gently combine the red velvet and white cheesecake batters to create a marbled and swirled effect.
Bake at 350° for 40 minutes or until the edges of the top layer are set but the center is still “wobbly” and not firm.
Remove dish from oven and allow the blondies to cool at least four hours or overnight.
Cut into bars to serve.
Refrigerate after four hours.