Nanaimo bars

Ingredients

• 1 box (15.5 oz) "Thick 'n Fudgy Deluxe Chocolate Chunk Brownie mix, 8x8 pan size"
• 1/4 cup vegetable oil
• 3 Tbsp water
• 1 egg
• 1/2 cup lightly packed coconut
• 1/2 cup unsalted butter, softened
• 3 cups powdered sugar
• 3 Tbsp vanilla custard powder (*
• 5 Tbsp milk
• 3 Tbsp butter
• 5 oz unsweetened chocolate
• 1/3 C walnuts, coarsely chopped