Preheat the oven to 350F/177C. Line the bottom of an 8-inch springform pan with parchment paper and spray the sides with a baking spray. Prepare the brownie base first. In a large mixing bowl, cream together the softened butter, sugar and vanilla for a few minutes until smooth. Add the eggs and mix again for a few minutes until well incorporated. Add the melted chocolate and mix again.

In a separate bowl, combine the dry ingredients: flour, cocoa powder, baking powder and salt. Sift the dry ingredients into the batter, then mix for about a minute, until all the ingredients are well combined. Transfer the batter into the prepared pan and spread it evenly to the edges using an offset spatula. Bake the brownie base in the preheated oven for 20 minutes.

Meanwhile, prepare the cheesecake batter. Place the softened cream cheese, sugar and vanilla into a large mixing bowl and beat on medium-high speed for 5 to 7 minutes, scraping down the sides of the mixing bowl often, until the cream cheese is smooth and fluffy. Next, add the heavy cream and eggs. Mix again for 2 to 3 minutes, scraping down the sides midway. Reserve approximately 1/2 cup of the plain batter in a separate bowl.

Into the remaining batter, add the cocoa powder and begin adding the red food coloring (I use concentrated gel color). You can add as much or as little as you would like. Mix the cocoa and food coloring into the batter, scraping down the sides of the mixing bowl to get all the batter incorporated.

Once the brownie base is done baking, remove it from the oven and wrap the bottom with a few layers of aluminum foil. Pour the cheesecake batter over the brownie and level off the top using an offset spatula. To create the swirled design, add dollops of the reserved batter on top, then use a knife to swirl the plain batter into the colored batter.

Prepare the water bath: transfer the springform pan into a large roasting pan or another deep baking pan. Fill the pan with approximately 1 inch of water. Reduce the oven temperature down to 320F/160C. Bake the cheesecake for 1 hour and 10-20 minutes; the center should be just slightly wobbly. Turn the oven off, crack open the oven door a bit and let the cheesecake sit for about an hour. Then, transfer the cake into the refrigerator and chill overnight.

For the whipped cream, simply combine the chilled cream, sugar, vanilla and a pinch of salt in a mixing bowl. Whisk on medium-high speed for 3 to 4 minutes, until stiff peaks form. Transfer the whipped cream into a piping bag tipped with a star tip; I used tip #8FT. Add dollops of whipped cream on top of the cake and on the side of each slice.