Tarte au Fromage Blanc

The tarte au fromage blanc (Käsekuchen in Alsatian) is the Alsatian cheesecake: a deep, open tart of fromage blanc custard on a sweet pastry base, baked until the filling is just set with a slight wobble and a faintly golden surface — lighter, tangier, and infinitely more elegant than the dense American or German cheesecake. This is the cake that appears at every family celebration, every Sunday lunch, and in every boulangerie window in Alsace, and it represents one of the most perfect uses of fromage blanc in the French pastry repertoire. The base is pâte sucrée or pâte brisée, rolled to 3mm and fitted into a deep-sided tart tin (24-26cm diameter, 4-5cm deep). The filling: 750g of fromage blanc (40% fat, drained in a sieve for 2 hours to remove excess whey — this draining step is critical for a firm, sliceable filling rather than a soupy centre), 150g sugar, 4 eggs (separated), 50g cornstarch or flour, the zest and juice of one lemon, a teaspoon of vanilla extract, and a pinch of salt. The egg yolks are whisked with the sugar until thick and pale, the drained fromage blanc folded in, then the cornstarch, lemon, and vanilla. The egg whites are beaten to firm peaks and folded in gently — this aeration produces the light, soufflé-like texture that distinguishes the Alsatian version from denser cheesecakes. The filling is poured into the pre-baked tart shell (blind-baked for 15 minutes at 190°C) and baked at 170°C for 40-50 minutes until the edges are set but the centre still wobbles gently when the tin is tapped. The tart must cool slowly in the turned-off oven with the door ajar for 30 minutes to prevent cracking, then at room temperature. Serve at cool room temperature, dusted with powdered sugar or accompanied by a compote of seasonal fruit — mirabelle compote in late summer is the canonical pairing.