Preheat the oven to 350F then line an 8x8 baking pan with parchment paper or foil. Set side.
In a large bowl, cream the butter, granulate sugar, and brown sugar together until smooth and creamy. Add in the egg, the vanilla extract, and mix to combine.
½ cup butter, ½ cup granulated sugar, 2 tablespoon brown sugar, 1 large egg, 2 teaspoon vanilla extract
Mix in the flour, baking powder, and salt just until the flour mixture barely disappears. Spread the batter into the prepared baking pan with an offset spatula and bake in the preheated oven for 15 minutes. The center will still look undercooked but don't worry these bars will continue baking as they cool down.
¾ teaspoon baking powder, 1 & ¼ cup all purpose flour, ¼ teaspoon salt
Cream Cheese Frosting
In a large bowl, whip the softened butter, and cream cheese together until smooth. Add in the powdered sugar and vanilla extract and mix again until light and fluffy.
Frost the sugar cookie bars with the cream cheese frosting and chill for 30 minutes to an hour then top with the fresh fruit. Slice and serve.
Fresh berries and fruit of choice
Notes
The cookie dough will be very soft and sticky that's why I recommend spreading it with an offset spatula. The softness of the dough will result in the softest cookie bars ever!