Preheat the oven to 180°C (Thermostat 6) and butter the cake mold.
Crush speculoos cookies (Bastogne type) using a mixer, pestle, or rolling pin. Distribute the crushed cookies at the bottom of the mold, pressing them firmly.
Mix 500 g of beaten white cheese (does not work with curds) with 100 g of powdered sugar, 1 tablespoon of cornstarch (or flour if unavailable), and 3 egg yolks. Add the zest of 1/2 lemon (adjust according to taste).
Beat the 3 egg whites until stiff and gently fold them into the mixture. Pour into the mold and bake for about 30 minutes.