Preheat oven to 180°C (356°F), using top and bottom heat.
Prepare the crust: Crush the butter biscuits until fine. Mix with melted butter and ground almonds. Press into the base of a greased 26 cm (10-inch) springform pan. Pre-bake the crust for 10 minutes.
Make the filling: In a large bowl, beat together cream cheese, quark (or Greek yogurt), sugar, and cornstarch until smooth. Add cream and lemon juice, and stir until well incorporated. Fold in the egg last.
Create the swirl: Puree 100 grams of strawberries. Pour the cheesecake filling over the pre-baked crust. Drop spoonfuls of strawberry puree over the surface and use a skewer or knife to gently swirl for a marbled effect.
Bake the cheesecake: Lower the oven temperature to 160°C (320°F) and bake for 50 minutes. After baking, turn off the oven and let the cheesecake sit inside for 15 minutes. Crack the oven door slightly and allow it to cool gradually.
Finish with sauce: Puree an additional 100 grams of strawberries. Once the cheesecake is completely cooled, pour the strawberry sauce over the top just before serving.