Speculoos Buckwheat Financier Stack

Toast hazelnuts (80g for praline) in a dry skillet over medium heat, stirring constantly, until golden and fragrant, about 5-6 minutes. Transfer to a clean kitchen towel and rub vigorously to remove skins. Let cool completely.

Toast remaining 30g hazelnuts for garnish the same way, then roughly chop and set aside.

In a light-colored saucepan, melt 100g butter over medium heat, swirling occasionally. Continue heating until the foam subsides and the milk solids turn golden-amber and smell nutty, about 5-7 minutes. Immediately pour through a fine-mesh sieve into a heatproof bowl to stop cooking. Set aside to cool slightly but keep liquid.

In a small saucepan, combine 30g butter, brown sugar, cinnamon, nutmeg, and cloves. Heat over low heat, stirring, until butter melts and sugar dissolves, about 2-3 minutes. Remove from heat and let cool to room temperature — it should be pourable but not hot.

Combine white sugar (50g for caramel) in a heavy saucepan. Heat without stirring until edges begin to melt and color shifts to amber, then swirl gently and cook to deep caramel (175°C/347°F). Immediately stir in toasted hazelnuts (80g), coating thoroughly. Pour onto a silicone mat or parchment-lined sheet. Let cool completely until hard, about 20-30 minutes. Break into pieces and process in a food processor until smooth praline paste forms, scraping sides as needed, 2-3 minutes.

Whisk egg whites and powdered sugar (120g) in a bowl until combined and slightly frothy, about 1 minute. Add vanilla extract.

In a separate large bowl, whisk together almond flour, buckwheat flour, all-purpose flour, and baking powder.

Pour egg white mixture into dry ingredients, stirring with a spatula until just combined — some lumps are fine.

Add the brown butter (beurre noisette) to the batter in a slow stream, folding gently until fully incorporated.

Fold in the speculoos spice paste until a smooth, homogenous batter forms. Cover and refrigerate for at least 30 minutes (or up to 24 hours for deeper flavor development).

Beat softened butter (100g) with an electric mixer on medium speed until pale and fluffy, about 3-4 minutes.

Add powdered sugar (150g) in two additions, beating well after each. Add vanilla extract.

Incorporate heavy cream and beat until smooth and airy, about 2 minutes more.

Fold in 2-3 tablespoons of the hazelnut praline paste until streaks of caramel color run through the buttercream. Reserve remaining praline for garnish.

Preheat oven to 190°C/375°F. Generously butter a 6-cup muffin tin or financier mold pan (or individual ramekins). Dust with a little buckwheat flour, tapping out excess.

Divide batter evenly among prepared molds, filling about 3/4 full.

Bake for 12-15 minutes, until edges are deeply golden and a skewer inserted into center comes out clean. Financiers should have risen with a slight dome and caramelized crust at edges.

Cool in pan for 5 minutes, then unmold onto a wire rack. They should release cleanly with a crisp exterior. Cool completely before stacking, about 20 minutes.

Place one financier as the base on your serving plate. Pipe or spread a generous layer of praline buttercream (about 2 tablespoons) on top.

Stack a second financier, pressing gently. Repeat with buttercream layer.

Top with a third financier. Finish with a final swoop of buttercream, then drizzle with reserved praline paste and scatter chopped toasted hazelnuts.

Serve immediately, or refrigerate for up to 2 hours. Bring to room temperature for 15 minutes before serving to enjoy the full nutty, spiced, caramelized flavor profile.