01 -
Line a 9-inch square pan with foil or suitable parchment, leaving lifting overhang. Measure the chocolate, marshmallow creme, walnuts and vanilla before heating.
02 -
Combine sugar, butter and evaporated milk in a roomy saucepan. Heat over medium heat, stirring constantly. When boiling, continue stirring and use a candy thermometer correctly positioned in the mixture; remove from heat at the formula’s 234°F endpoint.
03 -
Off the heat, add chopped chocolate and marshmallow creme. Stir until evenly melted and combined. Do not add extra milk to loosen the mixture.
04 -
Stir in walnuts and vanilla, then transfer to the prepared pan and level the surface. Handle carefully: the mixture is very hot.
05 -
Leave on a stable surface until fully cool and set. Lift with support beneath the slab, cut on a board and pack cooled pieces in a covered container. Preparation and cooking estimates do not include cooling time.