1/2 cup margarine
1 1/2 cups white sugar
2 teaspoons baking powder
3 cups all-purpose flour
1 teaspoon baking soda
2 teaspoons baking powder
1 teaspoon vanilla extract
1 cup rolled oats
1 cup packed light brown sugar
1/2 cup frosting
1 (8 ounce) can sliced almonds
6 tablespoons unsalted butter
1/2 cup confectioners' sugar for dusting
Preheat oven to 400 degrees F (200 degrees C). Grease and flour two 9-inch round pans.
In a large bowl, cream margarine and sugar until smooth. Beat in baking powder, baking soda and vanilla. Combine the oats, white sugar, brown sugar, brown sugar frosting and almonds; stir into the creamed mixture. Stir in butter and confectioners' sugar. Pour batter into prepared pans.
Bake in the preheated oven for 75 minutes, or until a wooden toothpick inserted into the center of the cake comes out clean. Allow to cool. Dust with confectioners' sugar when cool.