First, mix the red velvet cake crumbs with melted butter until well combined. Press the mixture firmly into the bottom of each lined muffin cup. I like to use the back of a spoon or a small glass to get an even crust layer.
Next, beat softened cream cheese and sugar until smooth using an electric mixer. Add the egg, sour cream, and vanilla extract, mixing until everything is creamy and uniform. I always scrape the sides of the bowl to make sure no lumps remain.
Spoon the cheesecake mixture over the red velvet crusts in each muffin cup. Fill each about three-quarters full so they have a nice dome when baked. Smooth the tops gently with a spoon for an even finish.
Bake the mini cheesecakes in a preheated oven at 350°F (175°C) for 18–20 minutes. I check them by gently shaking the pan—the centers should be slightly jiggly but not liquid.
Allow the cheesecakes to cool completely at room temperature, then refrigerate for at least 2 hours. I’ve found that chilling helps them set perfectly and enhances the flavors.