Pour boiling water over oats, set aside until cool. Cream butter with sugars, beat in eggs one at a time. Beat in orange juice concentrate and vanilla. Sift together flour, baking powder, baking soda, salt and cinnamon.
Blend into creamed mixture alternately with oats , beginning and ending with flour mixture. Fold in nuts.
Pour into greased 9X13 pan.
Bake 375 for 30-35 minutes or until cake tests done.
Cool and spread with COCONUT WALNUT TOPPING ( below)
Place under broiler for 1 minute until topping is golden brown and bubbly. Serve warm or cold.
COCONUT WALNUT TOPPING:
1/2 c butter or margarine
3/4 c brown sugar
2 Tbs frozen orange juice thawed and undiluted
1 c flaked coconut
1/2 c chopped walnuts
Melt butter and add brown sugar, and orange juice concentrate. Cook one minute, stirring constantly. Add coconut and walnuts. Follow instructions under cake instructions.