Preheat oven to 325°F (160°C). Line an 8×8 inch baking pan with parchment paper, leaving some overhang on the sides.
In a bowl, mix graham cracker crumbs, melted butter, and sugar until well combined. Press evenly into the bottom of the pan. Bake for 10 minutes. Let cool slightly.
In a large mixing bowl, beat the cream cheese and sugar until smooth. Add in the eggs one at a time, mixing well after each. Add vanilla and sour cream, and mix until combined. Pour over the cooled crust.
Blend the strawberries, sugar, and lemon juice until smooth. Strain through a sieve if desired for a smoother texture. Drop spoonfuls of the strawberry puree on top of the cheesecake batter and use a toothpick to swirl.
Bake for 30–35 minutes, or until the center is set and only slightly jiggly. Remove from oven and let cool at room temperature.
Refrigerate for at least 3 hours, or overnight for best results. Once chilled, lift the cheesecake out using the parchment paper and slice into bars.