Preheat your oven to 175 °C (177 °C). Lightly grease a 23cm (9-inch) springform pan. Line the base with parchment paper.

For the crust: Pulse graham crackers into fine crumbs in a food processor. Mix crumbs with melted butter and 30 ml sugar until evenly moistened.

Press the crumb mixture firmly and evenly into the bottom of the prepared springform pan. Bake for 10 minutes. Remove from oven and let cool completely on a wire rack.

For the filling: In a large bowl, beat the softened cream cheese with an electric mixer on medium-low speed until smooth and creamy, about 2-3 minutes. Gradually add 250 g sugar, scraping down the bowl as needed.

Beat in the flour, vanilla extract, lemon zest, and lemon juice until just combined.

Add the eggs and egg yolk one at a time, beating on low speed after each addition until just incorporated. Scrape down the bowl frequently.

Gently fold in the sour cream until the batter is smooth and homogenous. Pour the filling over the cooled crust, smoothing the top with a spatula.

Reduce oven temperature to 150 °C (149 °C). Bake for 50-60 minutes, or until the edges are set but the center has a slight wobble when gently shaken.

Turn off the oven. Leave the oven door slightly ajar and let the cheesecake cool inside the oven for 2 hours. This gradual cooling helps prevent cracking.

Remove cheesecake from the oven and let it cool completely on a wire rack at room temperature. Then, cover loosely with plastic wrap and refrigerate for at least 6 hours, preferably overnight.

For the berry coulis: Combine berries, 50 g sugar, and 15 ml lemon juice in a small saucepan. Cook over medium heat, stirring occasionally, until berries break down and sauce thickens slightly, about 10-15 minutes. Strain if desired for a smoother coulis.

To serve: Carefully run a thin knife around the edge of the cheesecake before releasing the springform pan. Slice and serve with the berry coulis.