Remove the cream cheese from the fridge 1 hour before baking so it softens completely—your finger should press in easily.

Place the butter in a small bowl and heat it in the microwave on medium-low for 30 seconds, or melt it over a double boiler until completely liquid.

Line the bottom of a 6-inch springform pan with a circle of parchment paper.

Preheat your oven to 180°C (356°F) and allow it to stabilize for 10 minutes.

Wash the blueberries and pat them thoroughly dry.

Add the Biscoff cookies to a bowl and crush them with a rolling pin until very fine with no big chunks left.

Pour in the melted butter and mix until every crumb is evenly coated.

Transfer the mixture into a 6-inch pan lined with parchment paper.

Press firmly using the bottom of a glass to compact the crust and build clean edges.

Freeze for 10 minutes to help the crust firm up quickly.

In a mixing bowl, combine the softened cream cheese and sugar.

Use a spatula to mix until smooth and lump-free.

Add the eggs, sift in the cornstarch, pour in the heavy cream, and mix on low speed with an electric mixer until fully combined and silky.

Remove the crust from the freezer and pour the batter in.

Tap the pan on the counter 3–5 times to release large air bubbles. Pop any visible bubbles on the surface using a toothpick.

Bake at 180°C for 30 minutes on the middle rack, until the edges are set and the surface is lightly golden while the center still jiggles.

Add the blueberries, sugar, and lemon juice to a small pot.

Cook over low heat, stirring constantly, until the berries soften, release their juices, and the sauce thickens slightly (about 5 minutes).

Remove from heat and transfer the blueberry sauce to a bowl. Let it cool to room temperature.

Never pour hot sauce onto your cheesecake.

Let the cheesecake cool fully to room temperature.

Unmold it, then pour the cooled blueberry sauce over the center of the cheesecake.

Spread gently with a spatula.

Refrigerate for at least 6 hours, preferably overnight, for optimal texture and flavor.