01 - Preheat oven to 350°F (175°C). Grease and line a 9-inch springform pan with parchment paper. In a medium bowl, whisk together the flour, granulated sugar, cocoa powder, baking soda, and salt. In a separate bowl, whisk together buttermilk, vegetable oil, egg, vanilla extract, white vinegar, and red food coloring. Gradually incorporate the wet mixture into the dry ingredients, stirring until a smooth batter forms. Pour the batter into the prepared pan and bake for 20–22 minutes or until a toothpick inserted in the center emerges clean. Allow the cake base to cool while preparing the cheesecake layer.
02 - Reduce oven temperature to 325°F (163°C). In a large mixing bowl, beat the softened cream cheese and granulated sugar until completely smooth and creamy. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract and sour cream until the batter is cohesive and silky. Pour the cheesecake mixture evenly over the cooled red velvet cake base in the springform pan.
03 - Place a shallow pan of hot water on the bottom rack of the oven to create steam, which helps prevent cracks in the cheesecake. Bake for 45–50 minutes, or until the edges are set but the center still has a slight jiggle. Turn off the oven and leave the cheesecake inside with the door slightly ajar for 1 hour. Remove and refrigerate the cheesecake for at least 4 hours, preferably overnight, to ensure proper setting.
04 - In a small saucepan over low heat, combine the strawberry jam or preserves with lemon juice, stirring until smooth and glossy. Remove from heat and allow to cool slightly. Arrange the fresh sliced strawberries on top of the chilled cheesecake, then drizzle the glaze evenly over the fruit for a decorative finish.
05 - Slice and serve the cheesecake chilled for optimal flavor and texture. Store any leftovers covered in the refrigerator.