Original Old Fashioned Mud Hen Bars

INGREDIENTS

1/2 cup

unsalted butter , softened at room temperature

1 cup

granulated sugar

large eggs , separated

1 tsp

pure vanilla extract

2 tbsp

half and half or milk

1 1/2 cups

all purpose flour

1 tsp

baking powder

1/4 tsp

salt

1 1/2 cups

chopped pecans

cream of tartar , optional

1 cup

light brown sugar , packed