Chocolate Hazelnut Cake

Roast whole hazelnuts first, that unlocks the oils and gives a much deeper toasty nutty note than raw nuts. Then either use a small amount of hazelnut flour (finely ground, blanched is best) in place of part of the plain flour, or swirl in a little hazelnut paste or gianduja into the filling or frosting for an unmistakable hazelnut punch. A tiny pinch of espresso powder also boosts chocolate and makes the hazelnut come alive.

Yep! roast for flavour, then rub off loose skins if you prefer a cleaner taste. Blanching (removing skins completely) and finely grinding the nuts yields a light, tender crumb without gritty brown flecks; if you do not have time, buying commercial hazelnut flour or meal is a reliable shortcut. Roasting first is the single biggest flavour upgrade people report.

You can use Nutella as a quick shortcut, but know it’s sweeter and oilier than pure hazelnut paste or gianduja. For a cleaner, less greasy finish use a proper hazelnut paste or gianduja in your ganache or buttercream; if you do use Nutella, use it sparingly or adjust the sugar and chill the frosting to stabilize texture. Many bakers prefer paste for a professional finish.

Overbaking and too much dry ingredient are the main culprits. Weigh flour and cocoa instead of scooping, avoid overmixing, and watch the cake rather than the clock - pull it when a skewer shows a few moist crumbs, not bone dry. You can also brush layers with a light syrup (coffee, hazelnut liqueur or simple syrup) to add moisture and flavour if needed. Using brown butter or a small amount of oil also helps keep the crumb tender.

Ganache is an emulsion and can split if overheated or the chocolate and cream are not combined gently. To fix a split or grainy ganache warm it slightly and whisk in a teaspoon of hot water at a time until it comes back together, or reheat gently and whisk vigorously. To avoid problems, heat the cream to just steaming (not boiling), pour it over finely chopped good-quality chocolate and let sit a minute before stirring into a smooth emulsion. Adding nut paste is fine but do it slowly and taste as you go so the fat content doesn’t break the emulsion.

Once assembled, store the cake in an airtight cake dome or covered loosely in the fridge if it has a cream or ganache coating, it will keep 3 to 5 days refrigerated. For longer storage, you can freeze slices well wrapped for up to 2 months; thaw overnight in the fridge and bring to room temperature before serving. If you plan to freeze, avoid heavy decorations that don’t travel well and consider freezing unfrosted layers then finishing with ganache when ready to serve.