Hi Faye,
From your description and the ingredients, it sounds as though you are referring to Nanaimo Bars.
These are very easy and delicious. Hope this is what you are looking for.

NANAIMO BARS

1/2 cup butter (do not substitute oleo)
1/4 cup sugar
3 Tbsp. cocoa
egg beaters to equal one egg ( the original recipe calls for one raw egg, but the USDA recommends using egg beaters in any recipe calling for raw egg, if the egg does not get cooked)
2 cups graham cracker crumbs
1/2 cup finely shredded coconut
1/2 chopped nuts

Melt butter and stir in remaining ingredients. Spread in the bottom of a 9" square dish. Chill

2 cups powdered sugar
1/4 cup butter (do not use oleo)
2 Tbsp. instant vanilla pudding powder
3 Tbsp. milk

Cream above ingredients together, adding just enough milk to get a soft icing consistency. Spread on top of chilled base. Chill at least 15 minutes.

3 squares semi-sweet chocolate
1 Tbsp. butter

Partially melt chocolate and butter. Remove from heat and stir until melted. Spread over custard layer. Chill. Makes 24 bars.
Score the chocolate with a sharp paring knife before it gets totally hard.
Store in fridge, covered, up to one month. Serve chilled.