Lightly grease the bottom and sides of a 9-inch springform pan. For easier removal, line the bottom with a round of parchment paper. Set the pan aside.

In a medium bowl, combine the graham cracker crumbs and granulated sugar. Pour in the melted butter and stir until all the crumbs are evenly moistened. The mixture should resemble wet sand and hold together when pressed.

Transfer the crumb mixture to the prepared springform pan. Press it firmly and evenly across the bottom using the flat bottom of a measuring cup or glass. Refrigerate for 20 minutes while you prepare the filling.

In a large mixing bowl, beat the softened cream cheese on medium speed for 2–3 minutes, until completely smooth. Add the powdered sugar, vanilla extract, and lemon juice. Beat again until creamy and free of lumps.

In a separate cold mixing bowl, beat the heavy cream on medium-high speed until stiff peaks form. The whipped cream should hold its shape when the beaters are lifted, but it should not look grainy or curdled.

Add one-third of the whipped cream to the cream cheese mixture and fold gently with a rubber spatula. Fold in the remaining whipped cream in two additions. Stop as soon as no white streaks remain. The filling should be thick, airy, and able to hold a soft mound on the spatula.

Spoon the cheesecake filling over the chilled crust: Spread it evenly to the edges and smooth the top with an offset spatula. Cover the pan without pressing plastic wrap directly onto the surface.

Refrigerate for at least 6 hours, preferably overnight. The center should feel firm and set when gently touched. Do not add the strawberry topping before the cheesecake has fully chilled.

Place the sliced strawberries, granulated sugar, and lemon juice in a small saucepan over medium heat. Cook for 2–3 minutes, stirring gently, until the strawberries begin releasing juice but still retain some shape.

In a small bowl, whisk the cornstarch and water together until smooth. Pour the slurry into the simmering strawberries while stirring. Cook for 1–2 minutes, until the liquid becomes glossy and thick enough to coat the fruit. Remove from the heat.

Transfer the topping to a heatproof bowl: Let it cool for about 10 minutes at room temperature, then refrigerate for at least 20 minutes. The topping should be completely cool before it touches the cheesecake.

Once the cheesecake is fully set, run a thin knife around the inside edge of the springform pan. Release and remove the outer ring. Transfer the cheesecake carefully to a serving plate if desired.

Spoon the cooled strawberry topping over the center of the cheesecake. Spread it gently, leaving a narrow border around the edge if you want the white filling to remain visible.

If desired, decorate with whipped cream and fresh strawberry halves. Slice into 12 portions with a sharp knife. For clean cuts, wipe the knife between slices.