Recipe: Purple potato cupcakes with molasses cream cheese frosting

Purple potatoes add an earthy flavor to these decadent spiced cupcakes with a rich, velvety frosting.

Purple potato cupcakes. All photos: Moriah VanVleet

Maybe it’s the kid in me, but whenever I buy a sack of assorted potatoes (the kind with a mix of petite, multicolored spuds), I find myself excited about the purple ones and hunt down the bag with the most of them.

Thanks to their unexpected burst of color and superbly syllabic name, purple potatoes bring a welcome whimsy to a menu. What’s more: their mild but earthy flavor is complex and delectable — and it’s not just meant for savory dishes.

In this recipe, purple potatoes are paired with ginger and orange peel, all grated into a succulent cake batter. With its distinctive depth, rich molasses is featured in both the cake and the cream cheese frosting, which itself is a dreamy indulgence. (The icing tastes like velvety gingerbread cheesecake on a spoon — ahem, I mean, on cake!)

While the potatoes lose their vivid color in the baking process, they take on a vibrant new life in the form of moist, tender cupcakes that flaunt a perfect balance of warm spice, bright citrus and mellow, earthy notes. The result is a scrumptious celebration of unexpected decadence.

Purple potato cupcakes with molasses cream cheese frosting

Makes 16-18 standard size cupcakes (see note)

Cupcakes:

1 medium orange
8 ounces purple potatoes (from about 5 small potatoes; see note)
1 tablespoon finely grated fresh ginger
2 large eggs
2/3 cup neutral vegetable oil, such as canola or sunflower
1/4 cup molasses (see note)
1 tablespoon pure vanilla extract
2/3 cup turbinado sugar
1 1/4 cups all-purpose flour
1 teaspoon baking soda
1/2 teaspoon salt
2 teaspoons dried ground ginger
optional: 2/3 cup total raisins and/or chopped nuts (preferably toasted hazelnuts, pecans or walnuts)

Molasses cream cheese frosting:

14 ounces cream cheese, softened
1/4 cup (2 ounces) butter, softened
2 tablespoons molasses
2 teaspoons dried ground ginger
1 1/4 cups powdered sugar
1/4 teaspoon salt (omit if using salted butter)

Preheat oven to 350ºF. Line muffin pans with 16-18 paper liners. Rinse, dry and finely zest the orange peel; set zest aside. Juice the orange, remove any seeds and measure out 2 tablespoons juice. Set aside, using any extra juice as you wish. Rinse and dry potatoes; no need to peel them. Grate with a standard size (large hole) grater; you should have 1 1/2 cups, well-packed.

In a large bowl, beat eggs and oil until smooth. Beat in the molasses and vanilla. Add the sugar and stir until evenly dispersed. Sift flour, baking soda, salt and ground ginger over the bowl. Begin to mix, alternately adding the 2 tablespoons of orange juice. Stop to scrape bowl with a rubber spatula occasionally. Fold in the grated potato, orange zest, and fresh ginger, mixing until just incorporated. If using, fold in the chopped nuts and/or raisins.

Fill the lined cups of the muffin pans 1/2 to 2/3 full. Bake for about 12-15 minutes, just until a toothpick inserted in the center tests clean, with no wet batter. Remove from oven and let sit in pan just until cool enough to handle, then transfer to wire racks or a towel on your countertop. Let cool completely before frosting.

Beat cream cheese and butter until completely combined. Add molasses and beat until evenly incorporated. Sift ginger, powdered sugar and salt over the bowl. Beat until smooth, occasionally stopping to scrape sides and bottom of bowl with a rubber spatula. Transfer frosting to a pastry bag and pipe it onto the cupcakes, or generously pile it onto the cooled cupcakes. Decorate with sprinkles if desired.

Recipe notes:

• If you add nuts or raisins, you’ll end up with a few more cupcakes.
• Be sure to use firm, small purple potatoes that are purple inside and out — not sweet potato, yam, ube or taro. While the sweeter varieties can be wondrous in desserts, this recipe relies on a minerally, savory flavor, crisp texture and thin skin.
• Blackstrap molasses can have an overpowering, off-putting intensity. I strongly recommend using a different variety of molasses for this recipe — not blackstrap. If your molasses is too thick to pour, warm it just slightly before measuring.
• While the frosting needs refrigerating if not eating within a few hours, the texture of the cake is optimal at room temperature. If possible, frost cupcakes just before serving. Store any leftover cupcakes unfrosted in a closed container at room temperature for up to two days, with the frosting tightly covered in the fridge.

Moriah VanVleet is the voice behind butter, sugar, flowers where this recipe first appeared. Follow her baking adventures on InstagramFacebook and Twitter.