Preheat and prepare: Preheat your oven to 160°C (140°C fan). Line a 20cm square baking tray with parchment paper, leaving an overhang on two sides for easy lifting. The paper should be smooth against the bottom and sides — any wrinkles will create uneven edges on your bites.

Make the crust: In a medium bowl, combine 120g almond flour, 30g coconut flour, and a pinch of salt. Pour in 50g melted butter and stir with a fork until the mixture looks like damp sand — it should clump together when pressed between your fingers. Press this mixture firmly into the bottom of the lined tray, using the flat bottom of a glass to compact it evenly. The crust should feel solid and uniform, about 1cm thick.

Blind bake the crust: Bake the crust for 10 minutes, until it turns a pale golden brown at the edges and smells nutty and toasted. Remove from the oven and let it cool on a wire rack for 10 minutes — do not skip this cooling step, or the filling will seep into the warm crust and become soggy.

Prepare the filling: In a large mixing bowl, beat the softened cream cheese and butter together with an electric mixer on medium speed for 2 minutes, until the mixture is pale, fluffy, and completely smooth — no white streaks should remain. Add the powdered erythritol and vanilla bean paste, then beat for another minute. The mixture should look glossy and smell intensely of vanilla.

Incorporate eggs and lemon: Add the eggs one at a time, beating on low speed after each addition until just combined — overbeating at this stage will incorporate too much air and cause cracks. Stir in the lemon juice and xanthan gum (if using) with a spatula. The batter should be thick, creamy, and smooth enough to spread, with a slight sheen on the surface.

Assemble and bake: Pour the filling over the cooled crust and spread it evenly with a spatula, reaching all four corners. Tap the tray gently on the counter twice to release any trapped air bubbles — you should see tiny bubbles rise and pop. Bake for 22–25 minutes, until the edges are set and lightly golden but the centre still jiggles slightly when you shake the tray. The surface should look matte, not wet or shiny.

Cool and chill: Let the cheesecake cool completely on a wire rack at room temperature for 1 hour — you will smell the vanilla becoming more pronounced as it cools. Then transfer to the refrigerator and chill for at least 2 hours, or overnight for the best texture. The filling should be firm to the touch and slice cleanly without sticking to the knife.

Slice and store: Lift the cheesecake out of the tray using the parchment overhang. Use a sharp, thin-bladed knife dipped in hot water and wiped dry between cuts to slice into 24 even bites. The edges should be clean and the layers distinct — a golden crust beneath a creamy, pale filling speckled with tiny black vanilla bean seeds.