Christmas Morning Coffee Cake - X Servings
Edited for clarity

Ingredients:
- Filling:
-- 4 tbsp melted butter
-- 4 tbsp flour
-- 1 cup brown sugar
-- 4 tbsp cinnamon
-- 2 cups chopped nuts (pecans)
- Batter:
-- 0.5cup butter, softened
-- 3 cups flour
-- 2 cups sugar
-- 4 egg yolks
-- 4 teaspoons baking powder
-- 0.5tsp salt
-- 1 cup milk
-- 2 tsp vanilla
- Other:
-- 4 egg whites

Preparation:

1) Pre-heat oven to 350F
2) Make filling first while butter softens:
-- 4 tbsp melted butter
-- 1 cup brown sugar
-- 4 tbsp cinnamon
-- 2 cups chopped nuts (pecans are good)
-- 4 tbsp flour
3) Make batter:
-- 0.5cup butter, softened - beat til fluffy
-- 2 cups sugar - add slowly while continuing to beat the butter
-- 4 egg yolks, separated (save egg whites for later) - add yolks one at a time
-- 3 cups flour, 4 teaspoons powder, 0.5tsp salt - blend together in separate bowl
-- 1 cup milk - alternate adding the flour mix & the milk to the butter mix - flour, milk, flour, milk, ending with flour
-- 2 tsp vanilla - mix in
4) Beat 4 egg whites with clean (not greasy) beaters till holding their shape [work quickly] 
5) Blend egg whites in to batter *gently*
6) Butter large pan (9"x13")
7) Spread batter and filling into pan in 2 alternating layers:
-- Pan - Spread 1/2 batter, sprinkle 1/2 filling, spread 1/2 batter, sprinkle 1/2 filling
8) Bake ~30 minutes, then check. May need 45 minutes.