In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the eggs one at a time, then stir in the vanilla extract.

In a separate medium bowl, whisk together the flour, salt, and baking powder.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Cover the dough and chill in the refrigerator for at least 30 minutes.

Preheat your oven to 350°F (175°C). Grease and flour a 9 or 10-inch round cake pan.

Press the chilled cookie dough evenly into the prepared cake pan.

Bake for 25-30 minutes, or until the edges are lightly golden brown and the center is set.

Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely.

In a large bowl, beat the softened cream cheese and butter together until smooth and creamy.

Gradually add the powdered sugar, mixing until well combined. Stir in the vanilla extract.

Add the milk (or cream) one tablespoon at a time, until the frosting reaches your desired spreading consistency.

Once the sugar cookie cake is completely cool, spread the cream cheese frosting evenly over the top.

Decorate with sprinkles, if desired.

Slice and serve!