Description

This rich, tender chocolate sponge is infused with a gooey peanut butter fudge filling and crowned with an airy peanut butter whip. It delivers all the nostalgic indulgence of a classic poke cake while remaining entirely free of added sugars.

Ingredients

Scale

Cake Base

1 1/2 cups (140g) finely ground blanched almond flour
2/3 cup (130g) granulated keto sweetener (such as erythritol blend)
1/3 cup (30g) unsweetened cocoa powder
1/4 cup (25g) unflavored whey protein powder
2 tsp baking powder
1/2 tsp instant espresso powder
1/4 tsp kosher salt
2 large eggs, room temperature
6 tbsp (85g) unsalted butter, melted and slightly cooled
1/2 tsp pure vanilla extract
1/2 cup (120ml) hot water

Peanut Butter Fudge Filling

1/2 cup (120ml) unsweetened almond milk
1 oz (28g) unsweetened baking chocolate, finely chopped
1/3 cup (85g) creamy unsweetened peanut butter
1/4 cup (30g) powdered keto sweetener

Frosting & Garnish

1/4 cup (57g) unsalted butter, softened to room temperature
1/3 cup (85g) creamy unsweetened peanut butter
1/3 cup (40g) powdered keto sweetener
1/8 tsp fine sea salt
1/2 cup plus 2 tbsp (150ml) heavy whipping cream, divided
4 sugar-free peanut butter cups, roughly chopped

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Instructions

Prep the equipment: Preheat your oven to 325°F (165°C). Lightly grease a 9×9-inch baking pan and set aside.
Mix the dry ingredients: In a large mixing bowl, whisk together the almond flour, granulated sweetener, cocoa powder, whey protein powder, baking powder, espresso powder, and kosher salt.
Form the batter: In a separate medium bowl, whisk the eggs, melted butter, and vanilla extract. Pour this into the dry ingredients and stir briefly. Pour in the hot water and stir until a smooth batter forms.
Bake the cake: Spread the batter evenly into the prepared baking pan. Bake for 20 to 25 minutes, until the cake has risen and the center feels firm and springs back slightly to the touch. Let the cake cool completely in the pan.
Prepare the fudge filling: In a small saucepan, bring the almond milk to a gentle simmer over medium heat. Remove from the heat, drop in the chopped unsweetened chocolate, and let it sit for about 2 minutes to melt. Whisk until smooth, then whisk in the peanut butter and powdered sweetener. Set aside 3 tablespoons of this mixture for garnishing later.
Poke and fill: Using the handle of a wooden spoon, carefully poke holes all over the cooled cake, spacing them about an inch apart. Pour the main batch of the peanut butter filling evenly over the top, gently spreading it so it seeps down into the holes. Refrigerate for 30 minutes to let the filling set.
Whip the frosting base: In a large mixing bowl, use an electric mixer to beat the softened butter, peanut butter, powdered sweetener, and sea salt until entirely smooth and creamy. Add 2 tablespoons of the heavy whipping cream and beat for another 30 seconds to lighten the mixture.
Fold in the cream: In a separate, clean bowl, whip the remaining 1/2 cup of heavy whipping cream until it holds stiff peaks. Gently fold the whipped cream into the peanut butter mixture, then beat on low speed just until combined and fluffy. Spread the frosting evenly over the chilled cake.
Garnish and chill: Sprinkle the chopped sugar-free peanut butter cups over the frosting. Gently warm the reserved 3 tablespoons of fudge filling (adding a few drops of water if it has thickened too much) and drizzle it over the cake. Refrigerate for at least 30 minutes before slicing to allow the frosting to firm up.

Notes

Why It Works

Using hot water in the cake batter blooms the cocoa powder and espresso, resulting in a much deeper, more robust chocolate flavor.
The whey protein acts as a structural binder, preventing the almond flour sponge from crumbling when poked and sliced.
A tiny pinch of sea salt in the frosting highlights the roasted peanut notes and balances the cooling effect of keto sweeteners.

Common Pitfalls to Avoid

Temperature shock: Ensure your eggs are at room temperature; cold eggs will instantly seize the melted butter, creating a lumpy batter.
Poking too deep: Only press the wooden spoon handle about three-quarters of the way down. If you poke all the way to the bottom of the pan, the filling will pool underneath the cake rather than marbling inside it.
Over-whipping the cream: Stop whipping the cream as soon as stiff peaks form. If over-beaten, it will curdle and make the frosting grainy.

Variations

Nut-Free Alternative: Swap the almond flour for sunflower seed flour (measure by weight), use coconut milk instead of almond milk, and substitute sunflower seed butter for the peanut butter.
Mocha Twist: Increase the espresso powder in the cake to 1 full teaspoon, and add a splash of cold-brew coffee to the frosting in place of the 2 tablespoons of un-whipped cream.

Allergy Alert

This recipe contains peanuts, tree nuts (almonds), dairy, and eggs. Substitute as needed.

Nutrition (per serving — estimates)

Calories: 267 | Total Carbs: 8g (Fiber: 4g, Sugar: 1g) | Net Carbs: 4g | Fat: 23g (Saturated: 9g) | Protein: 8g

Nutritional values are approximate, based on standard reference data (USDA FoodData Central). Actual values vary by brand and exact measurements. For precision, use a tracker like MyFitnessPal or Cronometer.

Nutrition

Serving Size: 1 slice
Calories: 267
Sugar: 1g
Fat: 23g
Saturated Fat: 9g
Carbohydrates: 8g
Fiber: 4g
Protein: 8g