Grind Walnuts: Chop or pulse the walnuts in a food processor until finely ground but not powdery—some small bits add texture.
2 cups walnut halves
Whip Egg Whites: Separate the eggs and beat the whites until stiff peaks form. Set aside.
4 large eggs
Mix Yolks and Sugar: In another bowl, beat the egg yolks with sugar until pale and fluffy.
¾ cup granulated sugar
Add Wet Ingredients: Mix in the softened butter and brewed coffee until smooth and creamy.
⅔ cup unsalted butter, 2 tablespoons brewed coffee
Add Dry Ingredients: Stir in the potato starch (or cornstarch) and baking powder until well combined.
⅔ cup potato starch, 1 tablespoon baking powder
Add Flavor and Mix-Ins: Gently fold in the orange extract, chopped candied orange peel, mini chocolate chips, and ground walnuts.
1 teaspoon orange extract or grated orange zest, ½ cup chopped candied orange peel, 4 candied cherries, ⅔ cup mini chocolate chips
Fold in Egg Whites: Add the beaten egg whites gradually, folding carefully from the bottom up to keep the batter light and airy.
Bake: Pour the batter into a greased and parchment-lined 9x5-inch loaf pan. Bake at 330°F (165°C) for about 50 minutes, or until a toothpick inserted in the center comes out clean.
Cool and Ice: Let the cake cool completely on a rack. Prepare the royal icing according to the package directions and spread it evenly over the top.
7 ounces royal icing mix
Decorate: Place the halved candied cherries on top. Add small holly leaves or more candied fruit if you’d like a festive touch.
Serve: Slice and enjoy! It’s perfect with coffee, tea, or any excuse to eat dessert before dinner.