4 tablespoons + 1 teaspoon unsalted butter, divided (plus additional for the pan)
1 (14-ounce) can sweetened condensed milk, divided
9 ounces semi-sweet chocolate, finely chopped, divided
1 1/2 teaspoons vanilla extract, divided
1 1/2 cups confectioners’ sugar, divided
1 cup creamy peanut butter
- Brush a 9-inch square nonstick baking pan with softened butter.
- Combine 3/4 cup of the sweetened condensed milk and 1 teaspoon of the vanilla extract in a small saucepan. Heat over low heat until hot. Remove from the heat and add 8 ounces of the chocolate, stirring until the mixture is smooth. Add 1/2 cup of the confections sugar, stirring until smooth. Spread the mixture in an even layer in the bottom of the prepared pan.
- Wipe out the saucepan. Combine the remaining 1/2 cup sweetened condensed milk, 4 tablespoons of the butter, and the remaining 1/2 teaspoon vanilla extract in the saucepan and place over low heat; stir until the butter melts. Remove the pan from the heat and stir in the peanut butter until smooth. Add the remaining 1 cup confectioners’ sugar, and stir until the mixture is smooth. Spread the peanut butter fudge in an even layer over the chocolate. Chill at least 2 hours.
- Melt the remaining 1 ounce of chocolate with the remaining 1 teaspoon butter in a small bowl in the microwave. Transfer the mixture to a zip-top plastic bag, pushing it down towards one corner. Snip about 1/8-inch of the plastic from the corner and squeeze the chocolate through the hole, creating a thin zigzag of chocolate over the top of the fudge. Allow the chocolate topping to set before cutting into 1-inch squares to serve.