Hazelnut Coffee Cake

This hazelnut coffee cake proves that a forgotten bag of pantry flour can turn into a genuinely impressive bakery-style bake with almost no advance planning. This hazelnut coffee cake recipe layers a rich coffee buttercream frosting over a tender, eggless nut-flour crumb, delivering everything a proper hazelnut crumb cake should taste like. Whether served for a Sunday breakfast or dressed up as a Nutella coffee cake with a chocolate swirl, this moist hazelnut coffee cake recipe earns a permanent spot in the regular rotation.

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Prep Time 20

Cook Time 45

Total Time 2 5

Servings: 8 slices

Course: Desserts

Cuisine: American

Ingredients Equipment Method Notes

Ingredients

For The Cake:

240 ml milk
2 tsp white vinegar
145 g light brown sugar
50 g cane sugar
2 tsp vanilla extract
80 ml vegetable oil
195 g all-purpose flour
190 g toasted hazelnut flour, see the toasting notes below.
2 tsp instant coffee granules , not a coffee-flavored cake, just enough to make the hazelnut taste deeper.
3 tsp baking powder
¼ tsp salt

For the Coffee Buttercream:

150 g butter softened - Dairy-free butter works if needed.
150 g powdered sugar
60 ml whipping cream
3 tsp instant coffee granules

Equipment

8-inch springform pan
Stand mixer or electric whisk
Food processor

Method

Toast your own hazelnut flour (optional):
Preheat the oven to 350°F (175°C) and toast whole hazelnuts for 7-8 minutes until fragrant. While still warm, rub them in a kitchen towel to knock most of the skins off, then pulse in a food processor with a tablespoon of sugar until finely ground. Stop before it turns into hazelnut butter - that happens faster than you think.
Preheat and prep:
Set the oven to 350°F (175°C) and grease your 8-inch springform pan.
Curdle the milk:
Whisk the milk and vinegar together and let it sit for 5 minutes until slightly curdled. It will look a little wrong. That is correct.
Build the wet mix:
Add the brown sugar, cane sugar, vanilla, and oil to the curdled milk and whisk until the sugar has dissolved.
Add the dry ingredients:
Mix in the flour, hazelnut flour, instant coffee, baking powder, and salt until the batter is smooth. Do not overmix, or the cake gets a little tough.
Bake:
Pour the batter into the prepared pan and bake for 45-50 minutes, until a toothpick inserted in the center comes out clean. If it is still gooey at 45 minutes, give it more time rather than pulling it early to hit some arbitrary deadline.
Cool completely:
Let the cake cool in the pan for 1 hour on a wire rack, then move it to a serving dish. This part requires actual patience, which I do not have, but I do it anyway because a warm cake melts buttercream instantly.
Make the buttercream:
Beat the softened butter until light and fluffy. Add the powdered sugar in two additions, beating until smooth each time. In a small bowl, dissolve the instant coffee in the whipping cream, then add that to the butter mixture and beat for 2-3 minutes until fluffy.
Assemble:
Spread the coffee buttercream over the cooled cake with an offset spatula, or the back of a spoon if that is what is clean. Top with chocolate shavings, chopped hazelnuts, or a dusting of cocoa powder.

Recipe Notes

Hazelnut flour: I use store-bought most of the time, since toasting and grinding my own only adds a slightly deeper flavor for a lot more effort.

Milk: I use dairy or a plant-based option like almond or oat, since both curdle fine with vinegar for this eggless coffee cake.

Instant coffee: I always use instant granules instead of ground coffee, since instant dissolves cleanly into both the batter and the buttercream.

Butter: I use dairy-free butter in the buttercream when I need a dairy free hazelnut coffee cake, and it whips up just as smoothly.

Vinegar: I use white vinegar to curdle the milk, though lemon juice works exactly the same way.