A great way to use up extra sourdough starter. We love this extra tall single-layer cake simply dusted with powdered sugar, but it can be frosted or cut into layers, then filled and frosted.

Have all ingredients at room temperature, about 70°F. Preheat the oven to 350°F. Coat a 9-inch springform pan with cooking spray and line the bottom with a round of parchment paper.

Whisk together in a medium bowl:

Beat in a large bowl, or in a stand mixer with the paddle attachment, until light and fluffy, about 5 minutes:

Beat in one at a time just until combined:

Whisk together in a medium bowl:

Add the flour mixture to the butter in 3 parts, alternating with the sourdough mixture in 2 parts, mixing until just combined and scraping down the sides of the bowl several times. Scrape into the prepared pan and bake until a toothpick inserted in the center comes out clean, about 40 minutes.

Let cool in the pan for 15 minutes. Run a thin knife around the inside of the pan to loosen the cake, then remove the pan ring. Cool the cake completely, then transfer to a serving platter. Before serving, dust with: