Prepare the Red Velvet Cake Layer: Preheat your oven to 350°F (175°C). Lightly grease a 9-inch springform pan and place a piece of parchment paper at the bottom. In a large bowl, beat together the sugar and softened butter until fluffy and light. In a separate bowl, whisk together the flour, cocoa powder, and baking soda. Gradually add the dry ingredients and buttermilk to the butter mixture, starting and ending with the dry ingredients. Stir in vanilla extract and red food coloring until fully combined. Place in the oven and bake for 20-25 minutes, checking with a toothpick in the centerLet the cake cool as you prepare the cheesecake layer.

Prepare the Cheesecake Layer: In a large bowl, beat the softened cream cheese and sugar together until smooth and creamy. Stir in the vanilla extract. Pour the cheesecake mixture over the cooled red velvet cake layer in the springform pan, spreading it evenly with a spatula. Bake for 30-35 minutes, or until the cheesecake is firm around the edges but still slightly wobbly in the center. Remove from the oven and allow it to cool to room temperature. Chill for a minimum of 4 hours, or overnight, to allow it to set completely.

Prepare the Strawberry Topping : In a small saucepan, combine the strawberry jam and water. Warm over low heat, stirring occasionally until the jam becomes smooth and fully melted. Remove from heat and let cool slightly, then stir in the sliced strawberries.

Optional Whipped Cream Topping In a mixing bowl, beat the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.

Assemble and Serve : Remove the cheesecake from the springform pan and transfer it to a serving plate. Top with the strawberry topping, spreading it evenly over the cheesecake layer. Add dollops of whipped cream around the edges (if using) for extra decoration.