Prep the pan and oven. Heat the oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment for easy release.

Mix the dry ingredients. In a large bowl, whisk 2 cups almond flour, 1/2 cup cocoa powder, 3/4 cup granulated keto sweetener, 1 1/2 teaspoons baking powder, 1/2 teaspoon salt, and 1 teaspoon espresso powder until no lumps remain.

Combine the wet ingredients. In a separate bowl, whisk 3 large eggs, 1/2 cup sour cream, 1/3 cup melted butter (slightly cooled), 2 tablespoons avocado oil, 1/3 cup unsweetened almond milk, and 2 teaspoons vanilla.

Bring it together. Pour the wet mixture into the dry mixture. Stir with a spatula until just combined. If using, fold in 1/2 cup sugar-free chocolate chips for extra richness.

Rest the batter briefly. Let the batter sit for 2–3 minutes. Almond flour and cocoa will hydrate and thicken the mix slightly, improving texture.

Bake. Spread the batter into the prepared pan and smooth the top. Bake for 22–28 minutes, or until the center is set and a toothpick comes out with a few moist crumbs.

Cool completely. Place the pan on a wire rack and cool for 15 minutes, then turn the cake out and remove the parchment. Let it cool fully before frosting or slicing.

Optional ganache. Warm 1/2 cup heavy cream to steaming (not boiling). Pour over 3/4 cup sugar-free chocolate chips with a pinch of salt and 1/2 teaspoon vanilla. Let sit 2 minutes, then stir until glossy. Spread over the cooled cake.

Slice and serve. Cut into 10–12 slices. For clean cuts, wipe your knife between slices.