'Not Nanaimo Bar' Squares - cooking recipe

Ingredients

1/2 cup peanut butter
1/2 cup brown sugar
1/2 cup corn syrup
2 cups cornflakes cereal
1 cup crispy rice cereal (such as Rice Krispies(R))
2 cups confectioners' sugar
2 tablespoons custard powder
1/2 cup margarine, melted
1 tablespoon warm water, or as needed
4 (1 ounce) squares semisweet chocolate, chopped
2 tablespoons margarine

Preparation

Grease an 8x8-inch square pan.
Cook and stir peanut butter, brown sugar, and corn syrup together in a large pot over medium heat just until warm and well blended, about 3 minutes; remove from heat. Stir cornflakes cereal and crispy rice cereal into peanut butter mixture; press cereal mixture evenly into the prepared pan.
Whisk confectioners' sugar and custard powder together in a bowl. Whisk 1/2 cup melted margarine gradually into custard mixture. Stir warm water into custard mixture to moisten to a spreadable consistency; spread evenly over cereal mixture.
Melt chocolate with remaining 2 tablespoons margarine in a microwave-safe bowl, about 1 minute. Pour chocolate mixture over custard layer. Refrigerate cookies until chocolate is hardened, about 30 minutes; cut into 1-inch squares.