Kraków Lattice Cheesecake (Sernik Krakowski)

// SUPPLY LIST

// OPERATIONS

1. 1 Make the shortcrust: rub or pulse the 300 g flour, 100 g icing sugar, baking powder and 1/4 tsp salt with the 200 g cold diced butter until it looks like coarse damp sand with a few pea-sized flecks, then add the 2 yolks and 1 tbsp cold sour cream and bring it together in no more than 20 seconds of pressing — it should just cohere when squeezed, still looking slightly rough. Do not knead it smooth: working warm dough develops gluten and bakes into a hard board instead of a short, sandy base. Divide it two-thirds / one-third, flatten both into flat rectangles, wrap and refrigerate at least 60 minutes (up to 2 days).
2. 2 Prepare the twaróg while the dough chills: if the block feels wet, wrap it in muslin, sit it in a sieve over a bowl with a 1 kg weight on top and press 2 hours in the fridge, then pass all 1 kg twice through the fine 3 mm plate of a mincer, or twice through a fine sieve with the back of a ladle, until it falls in soft fine threads with no lumps left. Do not blitz it in a food processor — the high-speed blade shears the curd and drives out whey, giving a wet, gluey, faintly rubbery filling instead of the fine dry crumb that is the point of sernik krakowski. Leave the ground cheese out on the worktop for a full hour before you mix the filling; cold cheese is the single commonest cause of a split, weeping batter.
3. 3 Put the 100 g raisins in a small bowl with the 3 tbsp rum or hot water and leave 20 minutes until plump and yielding, then drain thoroughly, pat dry on kitchen paper and toss with 1 tsp of the budyń or potato starch taken from the 40 g, so each one is dull and dusty rather than shiny — undried, uncoated raisins slide to the bottom of the tin and stew there in their own liquid.
4. 4 Heat the oven to 180°C / 350°F (fan 160°C / 320°F). Line a rectangular tin about 24 x 34 cm and at least 5 cm deep with baking paper, roll the larger dough piece between two sheets of paper to cover the base in an even 4-5 mm layer, press it in flat to the corners, prick it all over with a fork and chill 15 minutes. Blind bake it uncovered and unweighted for 15-18 minutes, until pale biscuit-gold, matt and dry to the touch but with no colour at the edges, then leave it in the tin to cool completely — filling laid on a warm base melts its butter and the crust turns to sand.
5. 5 Roll the smaller dough piece on its paper to a rectangle roughly 26 x 34 cm and 3 mm thick, slide it on the paper onto a board and refrigerate until firm. Rolling it to the full length of the tin now is what lets the lattice strips reach right across later; only cold, firm dough cuts strips that keep their edges instead of stretching and tearing as you lift them.
6. 6 Drop the oven to 160°C / 320°F (fan 140°C / 285°F). In a stand mixer with the paddle, beat the 200 g softened butter with the 220 g caster sugar on medium-high for 5-6 minutes until very pale, fluffy and no longer gritty between finger and thumb, then add the 6 yolks one at a time, beating 30 seconds after each. The butter must be at 20-21°C / 68-70°F and the twaróg at room temperature — cold cheese hitting warm butter splits the emulsion and the filling weeps fat as it bakes.
7. 7 Turn the mixer to medium-low and add the ground twaróg in five or six additions, scraping the bowl each time, beating only until smooth and homogeneous with no white flecks of unmixed curd — 3-4 minutes in total, no more. Overbeating at this stage pumps in air that inflates like a soufflé in the oven and then collapses into a cratered, cracked top as it cools.
8. 8 Beat in the remaining budyń or potato starch, the vanilla and the lemon zest on low for 30 seconds, just until no powder streaks remain. Budyń is the standard Kraków home version: it sets the filling a touch more reliably and adds the pale custard note Polish palates expect. Plain potato starch is the older version and gives a cleaner, tangier cake — either is correct.
9. 9 Whisk the 6 egg whites with 1/4 tsp salt until firm and glossy, holding a peak that curls over at the very tip — stop while they still look wet and satiny. Whites taken to dry, cottony stiffness break into lumps that no amount of folding disperses and bake into white streaks and tunnels through the filling.
10. 10 Fold the whites into the cheese mixture in three additions with a large spatula, cutting down through the middle and sweeping up the side, turning the bowl a quarter turn each stroke, until no white streaks remain but the mixture still holds a soft ribbon on the spatula. Fold in the raisins and the 50 g candied peel with the last few strokes, stopping the moment they are dispersed.
11. 11 Scrape the filling onto the cooled base, level the top with an offset palette knife and drop the tin flat onto the worktop three times from 5 cm to release trapped air; it should sit about 3 cm deep with clear headroom below the rim. Cut the chilled pastry sheet lengthways into strips 1-1.5 cm wide with a pastry wheel, lay one set straight across the short side of the tin at roughly 3 cm intervals, then a second set at right angles to form the kratka, trim the ends flush at the tin edge and brush the strips only with the yolk-and-milk glaze — glaze on the exposed filling bakes to brown patches.
12. 12 Bake on the lower-middle shelf at 160°C / 320°F (fan 140°C / 285°F) for 60-70 minutes. No water bath — a Kraków sernik is deliberately drier and firmer than a New York cheesecake, and steaming it softens the base. It is done when the lattice is deep gold, the filling is set and matt to within about 4 cm of the centre, that small centre wobbles as one slow unit like set custard rather than sloshing, and a probe in the middle reads 72-75°C / 162-167°F.
13. 13 Turn the oven off, wedge the door open with the handle of a wooden spoon and leave the cake inside 60 minutes; this slow fall in temperature is what stops the surface tearing and the middle sinking, and skipping it is the commonest reason home serniks crack. Move the tin to a rack for 2 hours until fully cool, then cover loosely and refrigerate at least 8 hours, ideally overnight — the crumb firms, the grain settles and the flavour rounds out; a warm sernik tastes raw and eggy and will not cut.
14. 14 Lift the cake out by the paper, dust the lattice with icing sugar through a fine sieve and cut into 16 pieces with a long thin knife dipped in hot water and wiped dry between every slice. Serve at cool room temperature — out of the fridge 30-40 minutes beforehand — with strong black tea or black coffee and nothing else on the plate; it keeps covered 4-5 days in the fridge and freezes well in slices for 3 months.

// CLASSIFICATIONS