Preheat oven to 350F and line a 12-cup muffin tin with cupcake liners. In a large bowl, whisk together gluten free flour, sugar, cocoa powder, baking soda, and salt.
In a separate bowl, whisk buttermilk, vegetable oil, eggs, red food coloring, white vinegar, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined with no lumps. Divide the batter evenly among the 12 cupcake liners, filling each about two-thirds full.
Bake for 18 to 20 minutes until a toothpick inserted in the center comes out clean. Let cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
For the frosting, beat cream cheese and butter together until fluffy. Add powdered sugar one cup at a time, then beat in vanilla extract until smooth and creamy.
Pipe or spread frosting generously on each cooled cupcake. Sprinkle with crushed red velvet cupcake crumbs if desired.