This might be the recipe you're thinking of:

PEANUTTY CHEWY BARS

1 1/4 cups unsifted flour
2/3 cup granulated sugar
1/3 cup unsweetened cocoa powder
1/4 cup light brown sugar, firmly packed
1 tsp. baking powder
1/4 tsp. salt
1/2 cup margarine or butter, cold
2 eggs, beaten
1 (10 oz.) pkg. peanut butter chips
1 (14 oz.) can sweetened condensed milk
1 cup flaked coconut

Preheat oven to 350 degrees. Stir together flour, granulated sugar,
cocoa, brown sugar, baking powder and salt. Cut in margarine until crumbly.
Add eggs; mix well. Spread in greased 13x9-inch pan. Bake 8 minutes.
Remove from oven; top evenly with chips then sweetened condensed milk and
coconut. Return to oven; bake 20 minutes or until lightly browned. Cool.
Garnish with Drizzle. Cut into bars. Store covered at room temperature.

Drizzle: Melt 1/2 cup semi-sweet chocolate chips with 1 1/2 tsp. shortening.