Preheat your oven to 325°F (165°C). Combine crushed digestive biscuits, melted unsalted butter, and granulated sugar until it resembles wet sand. Press into the bottom of a 9-inch springform pan. Bake for 10 minutes. Set aside to cool.

In a large bowl, beat softened cream cheese with sugar until smooth. Add eggs one at a time, mixing thoroughly after each. Fold in sour cream and vanilla extract. Pour over cooled crust.

Combine chopped strawberries, sugar, and lemon juice in a saucepan. Simmer for 8 minutes until strawberries soften. Mix cornstarch with water, stir into the compote, and cook for an additional 2 minutes until thickened. Let cool.

In a bowl, whisk flour and brown sugar. Cut in cold butter until mixture resembles coarse crumbs. Set aside.

Spoon cooled strawberry compote over cheesecake batter and sprinkle the streusel topping evenly. Bake for 60-70 minutes until edges are set and center has a slight jiggle.

Allow to cool in the oven with the door cracked for about an hour. Chill in the refrigerator for at least 6 hours or overnight.