Preheat oven to 350°F. Prepare a 9-inch springform pan with parchment paper at the bottom and grease the sides.

In a medium bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt.

In another bowl, combine milk, vegetable oil, vanilla extract, and egg white. Mix until combined.

Gradually add dry ingredients to wet ingredients, whisking until smooth.

Add hot water slowly, whisking until the batter is thin.

Pour batter into prepared pan and bake for 12-15 minutes, until a toothpick inserted comes out clean.

Remove cake from oven and cool on a wire rack.

Reduce oven temperature to 300°F. Prepare water bath if needed. Wrap springform pan in foil.

In a large bowl, beat cream cheese, sugar, and cocoa powder until smooth.

Add sour cream and vanilla, mix on low speed.

Add melted chocolate in parts, mixing after each addition.

Incorporate eggs one at a time, mixing slowly.

Add cooled cake layer to pan, then pour filling on top.

Place pan in larger roasting pan, fill with warm water about halfway up sides.

Bake for 1 hour and 15 minutes, center should be set but slightly jiggle.

Turn off oven, leave door closed for 30 minutes. Then crack the door to cool slowly.

Remove cheesecake, refrigerate until firm, at least 5 hours or overnight.

Once cooled, remove from pan and decorate with whipped cream and sprinkles. Chill until ready to serve.