Preheat oven to 325 F (160 C)
Put butter into a bowl. *Note: I suggest doubling the recipe if you want more. I know for next time to do so because it was gone that day*
Add in the brown sugar.
Now cream them together until smooth and creamy.
Add in vanilla.
And an egg.
Beat until smooth.
Mix in baking powder
If you'd like to add in nuts, chips, raisins, coconut, or chopped dried apricots, now is the time to add them.
Spread evenly in greased 8-inch square cake pan.
Bake for 40-45 minutes or until just set and golden.
Wait for them to cool completely before serving.