Preheat the oven to 350 degrees, locate ingredients, bring wet ingredients to room temperature (eggs and butter), and butter/grease a 9*9 inch square pan.
Melt the butter over the stove at low heat.
Then, stir in half of the brown sugar until smooth.
Add the remaining half of the brown sugar, stir, and remove from heat.
Allow the brown sugar and butter mixture to cool for 20-30 minutes before adding in eggs and vanilla extract; stir well.
In a medium mixing bowl, mix baking powder and salt with all purpose flour.
Add the dry ingredients to the wet; stir well. Then, place the mixture in the refrigerator for about ten minutes, stir, and refrigerate for an additional ten minutes.
Finally fold in optional ingredients.
Chocolate chips with chopped almonds/walnuts
White Chocolate Chips
White chocolate chips with chopped macadamia nuts
White chocolate chips with crushed candy canes
Pour batter into greased pan.
Bake for 18-22 minutes until golden brown and toothpick removes cleanly. Cool, cut, and serve.