Coffee Cake for Breakfast

This is from a cookbook I bought on road trip,  The Cowgirl's Cookbook:

2 2/3 c brown sugar
4 c unsifted flour
1 cup margarine
1 pint sour cream
1 lb raisins
1 cup chopped walnuts

Preheat oven to 350. Mix the sugar, flour and margarine, then with fingers mix until crumbly. Remove 1/2 cup of crumbles and set aside.  To the remaining mixture, add s cream, raisins, and nuts.  Stir and blend well (it will be thick).

Spread into a buttered 8X8 ovenproof dish. Top with the reserve crumbles.

Bake 80 minutes.

(I halved the recipe and cooked it about 45 minutes) It's a dense cake, and the raisins and walnuts make it so flavorful!