French Walnut Coffee Cake
Known in France as Gâteau Grenoblois, this French Walnut Coffee Cake is a specialty from Grenoble, in South Eastern France, where walnuts are plentiful. It features a fluffy crumb made with ground walnuts and is flavored with brewed coffee, all under a simple icing. This cake is naturally gluten-free and dairy-free, but delivers the same richness as any rustic French cake. If you love French regional cakes, add this one to your list! A favorite of French home bakers in the Fall, this cake recipe relies on walnuts to create…
- Prep time
- 20 min
- Cook time
- 45 min
- Yield
- 6 servings
- Difficulty
- MEDIUM
Ingredients
Quantities are shown as originally provided.
- 2 1/2 cups (250g) whole walnuts
- 5 medium eggs, at room temperature
- 1 cup (200g) sugar
- 2 tbsp (30ml) strong brewed coffee
- 2/3 cup (100g) cornstarch
- For the icing:
- 1 1/2 cup (150g) icing sugar
- 2-4 tbsp (30-60ml) strong brewed coffee
- Extra whole walnuts, for decorating
Instructions
- 1
Step 1 – Grind the walnuts and set aside. Make sure to keep 6-8 whole walnuts for decorating the cake.
- 2
Preheat your oven to 340°F (170°C) with a rack in the middle. Grease a 8” or 9” circular pan with butter (or dairy-free alternative) and line the bottom with a circle of parchment paper. Set aside.
- 3
Step 2 - Separate the egg whites and yolks in two different large baking bowls. Add the sugar to the egg yolks and whisk until fluffy and lighter in color. Add the brewed coffee and whisk to combine. Add the cornstarch and whisk until incorporated.
- 4
Step 3 - Switch to a spatula, and incorporate the ground walnuts. The batter will be rather thick and sticky.
- 5
Step 4 – In a separate and clean bowl, whisk the egg whites to a stiff peak. With the spatula, fold 1 scoop of the egg whites into the walnut batter to loosen its texture. Then, add about ¼ or less of the egg whites and fold gently. Stop mixing when just incorporated. In three or four more additions, fold in the rest of the egg whites. The batter should be airy and “jiggly”.
- 6
Step 5 – Pour the batter into the prepared pan. Bake for 40-45 minutes, until the cake is puffy and the center is set. Transfer onto a cooling rack, let cool completely and remove from the pan.
- 7
Step 6 – Prepare the icing. In a small bowl, combine the icing sugar with 2 tablespoons (30ml) of brewed coffee. Mix until smooth. Add more coffee – 1 teaspoon at a time - to thin out the icing. The icing should reach a thick syrup consistency. Pour the icing onto the cake and smooth it out with a spatula or the back of the spoon.
- 8
Add whole walnuts atop for decoration. Let the icing set for 1 hour at room temperature before serving.