In a medium bowl, combine flour, salt, and cocoa powder. Set aside.
Preheat the oven to 350℉/177℃. Grease two 8-inch round baking pans with baking spray. Line with parchment paper if desired, and set aside.
Cream the butter and sugar at high speed in a stand mixer until it’s fluffy and looks white (about 4 minutes). Then add sour cream and mix for another minute, followed by the oil – mix for another minute.
Add in eggs, one at a time, beating the mixture well between each addition.
Next, pour in the buttermilk, vinegar, and vanilla, and thoroughly mix.
Add food coloring until you reach the desired color.
Slowly add the flour mixture to the batter. Mix baking soda and water and gently fold into the cake batter. Scrape down the sides of the mixing bowl.
Divide the batter evenly between the two pans, tap on the countertop to release bubbles.
Bake at 350℉/177℃ for about 25-30 minutes or until a toothpick inserted in the cake comes out clean.
Let the cakes sit in their pans for 10-15 minutes. Gently place cakes on a wire rack and invert, lifting off the pan.
Once the cakes have completely cooled, wrap them in plastic paper and place them in the refrigerator for at least an hour or overnight. It makes it much easier to frost.
Line an 8" springform pan with parchment and spray with cooking spray. Preheat the oven to 325℉/163℃.
In a large bowl using a hand mixer, beat cream cheese and sugar until fluffy, 3-5 minutes. Add the sour cream and beat for about a minute.
Add eggs, one at a time, beating the mixture well between each addition. Next, add flour, salt, and vanilla and mix until thoroughly combined.
Pour the batter into the prepared springform pan. Wrap the springform pan in two layers of heavy-duty aluminum foil or save your foil and place the springform pan in a slightly larger pan filled with 1 inch of hot water.
Place the cheesecake into the preheated oven and bake for 50-60 minutes or until the edges are set and the center jiggles slightly.
Remove from the oven and let cool to room temperature, then transfer to the refrigerator to cool completely and firm up for at least 8 hours before assembling.