Ingredients

1 ½ cups shelled walnuts

¼ cup light olive oil

¼ cup brown butter or plain butter

¾ cup maple syrup

½ cup sugar

2 teaspoons vanilla extract

¼ teaspoon salt

5 large eggs (about 1 cup)

4 tablespoons grated lemon zest

1 ½ cups all-purpose flour

1 ½ cups baked sweet potato, mashed

4 teaspoons baking powder

For decoration (optional): confectioner’s sugar and citrus zest

Instructions

Step 1: Preheat the oven to 300ºF. Rinse and dry the sweet potatoes, then prick them several times with a fork. Wrap them in aluminum foil and place on a baking sheet. Bake for about 2 hours or until very soft when pierced with a knife. Allow to cool completely, then peel and mash the sweet potatoes. Set aside.

Step 2: Grease a 10-inch round bundt cake pan and dust it with flour. Set aside.

Step 3: In a food processor or blender, grind the walnuts with the olive oil until very smooth to create walnut butter.

Step 4: Transfer the walnut butter to a bowl and whisk in the brown butter. Add the maple syrup, sugar, vanilla, and salt, then beat until the mixture is fluffy.

Step 5: Add the eggs one at a time, beating well after each addition. Stir in the grated lemon zest.

Step 6: Sift together the flour and baking powder, then gently fold them into the wet mixture. Finally, fold in the mashed sweet potatoes until the batter has a slow dropping consistency.

Step 7: Pour the batter into the prepared bundt pan and bake for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean.

Step 8: Remove the cake from the oven and let it rest for a few minutes. Invert the bundt pan onto a serving platter to release the cake. Allow it to cool completely before serving.

Step 9: Optional: Dust the cooled cake with confectioner’s sugar and sprinkle with citrus zest for a decorative touch.

Tips & Variations

Use brown butter for a deeper, nutty flavor, made by melting unsalted butter and cooking until the milk solids turn light brown.

If you prefer, substitute honey for maple syrup but reduce the baking temperature to avoid over-browning.

Adding a teaspoon of cinnamon or nutmeg can enhance the warm flavors of the cake.

For a gluten-free version, substitute all-purpose flour with your favorite gluten-free blend.

FAQs

Can I use canned sweet potatoes instead of baking fresh ones?

While canned sweet potatoes can work in a pinch, freshly baked and mashed sweet potatoes offer better texture and flavor for this cake.

Why is the cake baked at a lower temperature?

The lower baking temperature helps prevent the cake from browning too quickly due to the natural sugars from maple syrup and sweet potatoes, ensuring a moist and tender result.