Step 1

Butter an 8 by 8-inch baking dish. Line with parchment paper and butter parchment, set aside.

Step 2

For the first layer: Melt butter in large heat proof bowl set over a saucepan of simmering water set over medium-low heat.

Step 3

Remove from heat, add in sugar, cocoa powder and salt and whisk until well combined. While whisking vigorously, very slowly pour in beaten egg in a thin stream.

Step 4

Return mixture to heat and cook until mixture has just thickened.

Step 5

Remove from heat and add in graham cracker crumbs, coconut, and almonds and toss until evenly coated.

Step 6

Press mixture into prepared baking dish. Chill while preparing the filling, bottom layer shouldn't be warm when adding the custard frosting layer.

Step 7

For the second layer: If you are using the custard powder option then simply add powdered sugar, butter, custard powder and 2 Tbsp heavy cream to mixer fit with paddle attachment. Whip until very pale and fluffy while adding another 1 Tbsp cream to thin if needed.

Step 8

If you are using the powdered milk option, add 1/4 cup powdered milk and 3 Tbsp heavy cream to the bowl of an electric stand mixer. Whisk vigorously to dissolve powdered milk. Add in butter, powdered sugar and vanilla, set mixer with paddle attachment and beat mixture until very light and fluffy.

Step 9

Spread mixture into an even layer over bottom layer. Chill preferably in the freezer while melting chocolate (otherwise the warm chocolate can melt this layer).

Step 10

For the third layer: Melt semi-sweet chocolate along with butter in a heat proof bowl, set over a pot of simmering water until smooth (or in the microwave in a microwave safe bowl in 20 second intervals stirring between each, until melted and smooth).

Step 11

Spread mixture into an even layer over filling layer (spread quickly before chocolate begins to set). Chill until chocolate has set.

Step 12

Cut into squares (tip for best appearance, cut squares from side to side rather than cutting downward). Store in an airtight container in refrigerator, bring to room temperature before serving.