Description
This Sweet Potato Butter Cake combines the natural sweetness of roasted sweet potatoes with a rich buttery cake base, enhanced by warm spices like cinnamon, nutmeg, and ginger. Topped with a luscious sweet potato butter glaze, this cake offers a moist, flavorful dessert perfect for any occasion. Its unique use of sweet potato puree in both the batter and frosting delivers a velvety texture and a delightful depth of flavor, making it a comforting and elegant treat.
Ingredients
Scale
Sweet Potato Puree
- 2 medium sweet potatoes (about 400–450 g total), scrubbed
- 2–3 tbsp milk or cream
- 1 tbsp unsalted butter
- 1–2 tbsp brown sugar (optional, to taste)
- Pinch of salt
Cake
- 1 3/4 cups (220 g) all-purpose flour
- 1 1/2 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp fine sea salt
- 1 tsp ground cinnamon
- 1/4 tsp ground nutmeg
- 1/4 tsp ground ginger (optional)
- 1/2 cup (115 g) unsalted butter, softened to room temperature
- 1/2 cup (100 g) granulated sugar
- 1/2 cup (100 g) light brown sugar, packed
- 2 large eggs, at room temperature
- 1 tsp pure vanilla extract
- 1/2 cup (120 ml) whole milk, at room temperature
- 1 cup (220 g) sweet potato puree (from above, cooled to room temperature)
Sweet Potato Butter Glaze/Frosting
- 1/4 cup (60 g) sweet potato puree (reserved from above)
- 6 tbsp (85 g) unsalted butter, very soft
- 1 1/2–2 cups (180–240 g) powdered sugar, sifted
- 1–2 tbsp milk or cream, as needed
- 1/2 tsp vanilla extract
- Pinch of salt
- Optional: 1/4 tsp cinnamon for a spiced glaze
Optional Toppings
- Toasted pecans or walnuts, roughly chopped
- A drizzle of honey or maple syrup
- Flaky sea salt for finishing
Instructions
- Prepare the sweet potato puree: Preheat your oven to 400°F (200°C) and line a small baking tray with foil. Pierce the sweet potatoes several times with a fork and bake them on the tray for 45–60 minutes, or until very soft when pierced with a knife. Let them cool enough to handle, then peel off the skins and place the flesh in a bowl. Add 1 tbsp butter, 2–3 tbsp milk or cream, a pinch of salt, and brown sugar if desired. Mash until completely smooth and velvety, using a blender or food processor for extra smoothness. Measure out 1 cup (220 g) of puree for the cake and 1/4 cup (60 g) for the glaze, letting both cool to room temperature.
- Prepare the cake pan: Reduce oven temperature to 350°F (175°C). Grease a 9-inch (23 cm) round cake pan or an 8×8-inch (20×20 cm) square pan with butter. Line the bottom with parchment paper and lightly flour the sides, tapping out excess flour.
- Mix the dry ingredients: In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, cinnamon, nutmeg, and ginger if using. Set this mixture aside.
- Cream the butter and sugars: In a large mixing bowl, beat the softened unsalted butter, granulated sugar, and light brown sugar with a hand or stand mixer on medium speed for 3–4 minutes until light, fluffy, and pale. Scrape down the sides as needed.
- Add eggs and flavoring: Add the eggs one at a time, beating well after each addition until fully incorporated. Then beat in the vanilla extract. Mix in the 1 cup cooled sweet potato puree at low speed until smooth and evenly combined, forming a thick and creamy batter.
- Combine wet and dry ingredients: Add half of the dry ingredients to the sweet potato batter and mix on low speed just until combined. Pour in the milk and mix gently until mostly incorporated. Add the remaining dry ingredients and mix on low speed until no flour streaks remain, taking care not to overmix.
- Bake the cake: Pour the batter into the prepared pan and smooth the top with a spatula. Tap the pan gently on the counter to release air bubbles. Bake for 28–35 minutes depending on pan size, until a toothpick inserted in the center comes out clean or with a few moist crumbs. Remove from oven and cool in the pan on a wire rack for 15 minutes. Run a knife around the edges, invert the cake onto the rack, peel off parchment, and flip the cake upright. Let it cool completely before glazing.
- Make the sweet potato butter glaze/frosting: Beat the softened butter in a medium bowl until creamy. Add the reserved 1/4 cup sweet potato puree and blend until silky. Gradually add 1 1/2 cups sifted powdered sugar while mixing on low speed, then increase to medium until smooth. Stir in vanilla extract, a pinch of salt, and cinnamon if desired. Add milk or cream 1 teaspoon at a time to achieve desired consistency—thinner for a pourable glaze, thicker for a spreadable frosting. Add remaining powdered sugar if you want a stiffer, sweeter frosting and beat again.
- Glaze and decorate the cake: Place the cooled cake on a serving plate. Pour or spread the sweet potato butter glaze over the top, allowing it to gently drip down the sides if pourable. While the glaze is still soft, sprinkle with toasted pecans or walnuts if using. Optionally drizzle honey or maple syrup and finish with flaky sea salt.
- Serve and store: Let the glazed cake set at room temperature for 20–30 minutes so the glaze firms slightly. Slice with a sharp knife, cleaning the blade between cuts for neat slices. Store leftovers covered at room temperature for up to 2 days, or refrigerate for up to 5 days. Bring chilled slices to room temperature before serving. The cake can be wrapped well and frozen (without glaze) for up to 2 months; thaw overnight in the fridge and glaze before serving.
Notes
- The brown sugar in the sweet potato puree is optional and can be adjusted for sweetness.
- Ensure sweet potato puree is fully cooled before mixing into the cake batter to prevent curdling.
- Do not overmix the batter once flour is added to maintain cake tenderness.
- The glaze consistency can be adjusted with milk or powdered sugar depending on whether you prefer it pourable or spreadable.
- For extra flavor, lightly toast nuts before adding as topping.
- Store cake without glaze if freezing, then add glaze after thawing for best texture.
