Preheat oven to 375°F. Butter and flour a 9x13 baking pan
Cream butter, add confectioners' sugar, and 2 c flour. Blend, mixture will look like coarse meal.
Pat into pan, bake 15 min.
Beat eggs, add brown sugar, vanilla. Beat until thick. Mix remaining 4 Tbsp flour, salt, baking powder, add to egg mixture.
Beat in nuts/chips/coconut (end up with 4 c of this mixture). Add coconut milk, 1 c oatmeal.
Spread evenly over pastry base, then bake 25–30 minutes. Cool in pan, cut into squares and enjoy.
A PTA bake sale classic.