Prune Whip Spice Cake with Prune Butter Frosting

This is old-school baking at its finest. A spice cake made moist with prune juice and warming spices, frosted with a butter frosting that folds in chopped cooked prunes and nuts. It’s the kind of recipe your grandmother clipped from a magazine and made every fall.

Prune juice in the batter does double duty. It adds moisture that keeps the crumb tender for days, and it deepens the flavor of the cinnamon, nutmeg, and allspice in a way that milk alone can’t.

The frosting is where this cake really stands apart. Creamed butter beaten with powdered sugar, lemon juice, and more prune juice creates a tangy, fruity base. Then you fold in the chopped cooked prunes and nuts for texture and bursts of concentrated fruit flavor in every bite.

Both the cake and frosting freeze well, so this is a great make-ahead dessert for holidays or potlucks.

Chef Tips

• Drain the cooked prunes thoroughly before folding into the frosting. Excess moisture will make the frosting runny and slide off the cake.
• Beat the batter on slow to medium speed, not high. Overbeating toughens the crumb. Follow the timing in the directions closely.
• Grease and flour both pans well. This batter is sticky from the prune juice and will cling to unprepped pans.
• Let the layers cool completely before frosting. Warm cake melts the buttercream and you’ll end up with a lopsided, sliding mess.

Variations

• Cream cheese frosting swap: Replace the butter with cream cheese for a tangier, denser frosting that pairs beautifully with the spiced cake.
• Add walnuts to the batter: Fold chopped walnuts into the cake batter for extra crunch throughout.
• Date substitution: Swap the prunes for chopped dates and use date syrup in place of prune juice for a similar but slightly sweeter flavor profile.