Peanut Butter - Fudge Marble Cake

This marble cake starts with a fudge marble mix but takes a sharp turn with melted peanut butter chips stirred into the vanilla batter. The result is a two-toned layer cake where every slice reveals swirls of rich chocolate running through a peanut butter base.

Melting the peanut butter chips in a double boiler with a little oil is the step that makes this work. Direct heat will scorch them, but gentle steam heat melts the chips into a smooth, pourable consistency that blends evenly into the batter. Once incorporated, the peanut butter batter goes into the pans first, then spoonfuls of the chocolate batter get dropped on top and swirled through.

Don’t over-swirl. A few passes with a knife or skewer give you those dramatic marble patterns. Too much mixing and you just end up with a muddy brown cake.

Pro Tips

• Use hot, not boiling, water in the double boiler. Boiling water can overheat the chips and make them seize into a grainy paste.
• Let the layers cool in the pans for the full 15 minutes before turning out. Peanut butter batter is softer than standard cake and needs that resting time to set.
• A chocolate frosting or peanut butter buttercream both work beautifully here. Or keep it simple with a dusting of powdered sugar.
• Test for doneness with a wooden pick in the center. The peanut butter layer can look underdone even when it’s finished, so trust the toothpick.

Variations

• Chocolate peanut butter cup cake: Fold chopped peanut butter cups into the batter before swirling for chunks of candy in every slice.
• Banana marble cake: Add a mashed ripe banana to the peanut butter batter for a PB and banana combo.