Biscoff Mocha Sheet Cake

5 from 3 votes

Biscoff cake with a mocha flavored caramel soak, Biscoff cookie butter spread and mocha buttercream.

Course: Dessert

Keyword: biscoff, Biscoff Cake, Biscoff Mocha, Biscoff Mocha Sheet Cake, Mocha buttercream, sheet cake

1 cup (200 g) granulated sugar
1/2 cup (120 g) water
2 teaspoons (14 g) light corn syrup or honey
1 cup (240 g) heavy whipping cream
2-3 teaspoons (12 g) coffee extract or emulsion OR 2-3 teaspoons espresso powder (6 g) OR 3 teaspoons Pero for a non coffee substitute
1 teaspoon (4.2 g) vanilla extract
1 teaspoon (6 g) salt

2 cups (452 g unsalted butter, slightly cold
6 cups (750 g) powdered sugar, measured and then sifted
5 teaspoons (21 g) coffee extract or emulsion OR 5 teaspoons espresso powder (10 g) OR 5 teaspoons Pero for a non coffee substitute
1/4 cup (57 g) heavy cream
Pinch of salt
***If you would rather spread the buttercream on the cake with an offset spatula than pipe it, I would suggest doing half a batch of buttercream.

Preheat your oven to 325 degrees F. Spray your 9-inch by 13-inch cake pan with non-stick cooking spray, line the bottom with parchment and spray again. Set aside.
Place the Biscoff cookies in a food processor or blender and pulse until the cookies are finely ground and resemble sand.
In a medium-size bowl, combine the Biscoff crumbs, all-purpose flour, baking powder, baking soda, and salt. Whisk until the ingredients are well-blended. Set aside.
In the bowl of a stand mixer fitted the paddle attachment, beat the butter, brown sugar and granulated sugar on medium speed until light and fluffy. Add the eggs, one at a time, beating well after each addition.
Before adding the dry ingredients, continue to beat the wet ingredients for about 1 to 2 minutes on medium-high speed, until the mixture is smooth.
With the mixer on low speed, add 1/3 of the dry ingredients and mix until combined. Slowly add half of the buttermilk and mix until incorporated. Continue alternating the flour and buttermilk until it has all been incorporated. Scrape down the sides of the bowl and slowly mix for another 20-30 seconds.
Pour the batter into the prepared pan. Bake for 35 to 40 minutes. Cool 15 to 20 minutes on a wire rack before inverting onto a cooling rack to cool completely.

Heat the cream in the microwave for about a minute. If you’re using espresso powder or Pero, whisk in the powder until it dissolves. Set aside.
Combine the sugar, water, and corn syrup in a saucepan over medium heat. Stir until sugar is dissolved and then stop stirring.
You want the mixture to cook on its own. Stirring creates crystallization. If you notice sugar crystallizing on the sides of the pan, soak a pastry brush in warm water and run the brush along the sides of the pan where the sugar is building up.
Once the mixture turns amber in color, remove the pan from the heat and slowly add the cream, while stirring the caramel.
Add the vanilla and salt, and stir to combine. If you’re using coffee extra or emulsion, add it here as well.
Cool to room temperature before using. The caramel will thicken as it cools but should still be thin enough to act as a “soak.” If you need to thin it out more, heat another 1/4 cup heavy whipping cream and add the caramel. Stir to combine. Let cool to room temperature again before using.

In the bowl of an electric mixer, fitted with the paddle attachment, beat the butter for about 2 to 3 minutes, until light and fluffy and pale in color.
With the mixer on slow, gradually add the powdered sugar, followed by the heavy cream, coffee emulsion, and pinch of salt.
IF YOU’RE USING ESPRESSO POWDER OR PERO, heat the cream slightly and whisk the espresso powder or Pero into the heavy cream. Add to the butter and powdered sugar mixture when the cream is at room temperature or cold again.
Once all of the ingredients are combined, turn the mixer to medium-high and beat for about 3 to 5 minutes.
Before using the buttercream, make sure to beat it by hand with a wooden spoon or large spatula to help push out the air pockets.

Once the cake has cooled to room temperature, use a fork to poke holes all over the cake.
Drizzle the caramel soak over the cake, using a pastry brush or the back of a spoon to spread it around, ensuring it soaks into the holes.
Using an offset icing spatula or the back of a spoon, spread the Biscoff cookie butter over the cake. If needed, heat the Biscoff spread slightly in the microwave to make it more spreadable.
Sprinkle on crushed Biscoff cookies and pat them into place gently.
Using the Wilton 6B piping tip, pipe the buttercream on the cake. Alternatively, use an offset icing spatula to spread on the buttercream.