Preheat your oven to 350°F (175°C). Grease the sides and bottom of a springform pan lightly.

In a large mixing bowl, combine softened cream cheese and granulated sugar with an electric mixer until smooth and creamy, about 2-3 minutes.

Add each egg one at a time, mixing on low speed after each addition until just combined. Stir in sour cream, vanilla extract, and cocoa powder until fully blended.

In a separate bowl, combine the strawberry puree, additional tablespoon of sugar, and lemon juice. Whisk until smooth.

Pour half of the chocolate cheesecake batter into the greased springform pan. Drizzle some strawberry puree over the chocolate layer and repeat with the remaining batter and puree.

Use a knife to gently swirl the mixtures together, creating a marbled effect.

Bake for 50-60 minutes. The cheesecake is done when the edges are set but the center jiggles slightly.

Turn off the oven and let the cheesecake cool inside with the door slightly ajar for 1 hour.

Let the cheesecake reach room temperature, then refrigerate for at least 4 hours or overnight.

Remove from the springform pan and garnish with fresh strawberries or chocolate sauce before slicing.