Italian Rum Cake (Torta al Rum)

Make the sponge cake: Preheat oven to 375°F (190°C). Butter and flour an 18-inch square pan (or use parchment).

Beat egg yolks and sugar until thick and pale yellow — this is crucial and takes 10-15 minutes. The mixture should ribbon when lifted and be doubled in volume (trust me, don't rush this step). (The mixture should be thick enough to write your name in it and have it hold for a few seconds.)

Gently fold in the sifted flour, a little at a time, then fold in vanilla and lemon zest.

Beat egg whites to stiff (but not dry) peaks. Fold 1/3 of the whites into the yolk mixture to lighten it, then gently fold in the remaining whites in two additions. (Use a large spoon or spatula and cut down through the center, across the bottom, and up the side. Rotate the bowl as you fold.)

Pour into prepared pan and bake 15-35 minutes until a toothpick comes out clean. Cool completely on a rack.

Make vanilla pastry cream: Whisk together sugar, egg yolks, flour, vanilla, and lemon zest in a heavy saucepan.

Heat milk to just under a boil. Very slowly pour hot milk into the egg mixture, whisking constantly to prevent curdling. (Pour in a thin stream and whisk like your life depends on it — scrambled eggs in pastry cream is not the vibe.)

Return to heat and cook on low, stirring constantly with a wooden spoon, until mixture boils. Cook 4 minutes more, stirring constantly.

Remove from heat, whisk in butter until smooth. Press plastic wrap directly onto surface to prevent a skin forming. Chill until thick (3-4 hours).

Make chocolate pastry cream: Follow the same process as vanilla cream, but add the chopped chocolate after the 4-minute cooking time. Stir until melted and smooth, then add butter.

Make rum syrup: Combine water, sugar, and rum in a small saucepan. Bring to a boil, stir until sugar dissolves, then cool completely.

Make stabilized whipped cream: Sprinkle gelatin over cold water in a small bowl. Let bloom for 5 minutes, then microwave for 30 seconds to dissolve (or use a double boiler). Cool slightly.

Whip cold cream with chilled beaters until it starts to thicken. Add sugar and vanilla, whip to soft peaks. With mixer running, slowly pour in cooled gelatin. Whip to stiff peaks.

Assembly time: Using a long serrated knife, carefully slice the cooled sponge cake horizontally to create 4 thin layers (honestly, this is the trickiest part — go slow). (Mark the sides of the cake with toothpicks as guides to keep your cuts level.)

Place first layer on serving platter, cut side up. Brush with 1/4 of the rum syrup — enough to moisten but not soak (soggy cake is sad cake).

Spread vanilla pastry cream evenly over first layer. Top with second cake layer, brush with syrup.

Spread whipped cream over second layer, top with third cake layer, brush with syrup.

Spread chocolate pastry cream over third layer, top with final cake layer, brush with remaining syrup.

Frost top and sides with remaining whipped cream. Cover and refrigerate at least 1 hour before serving (overnight is even better).