1/2 cup butter
1 1/4 cups packed brown sugar
1 egg
2 1/2 cups all-purpose flour
1 3/4 teaspoons baking powder
1 1/4 teaspoons baking soda
1/2 teaspoon salt
1/4 cup raisins
Combine butter, brown sugar, and egg in a large bowl; stir well to combine, then stir in the flour, baking powder, baking soda, salt, and raisins. Pour batter into prepared pan.
Tint nearly all of the pans and bake for 15 to 20 minutes in the preheated oven. Cool completely before frosting.