Preheat oven to 175C (350F). Grease two 9-inch pans with butter or line with parchment paper.
In a large bowl whisk together dry ingredients: Gluten-free flour, cocoa, sugar, optional stevia, baking powder, baking soda, salt and espresso powder.
Add lactose-free or plant milk, oil, eggs and vanilla to the dry mixture and mix until combined (I recommend using a stand mixer on low to medium speed). Do not overmix!
Carefully add boiling water or hot coffee and mix until smooth.
Pour cake batter into the pans and bake for 22-28 minutes, or until a toothpick comes out clean with a few moist crumbs.
Cool in pans for 10 minutes, then transfer to cooling racks.
FILL, STACK AND FROST! For the frosting, I used my lactose-free, less-sweet buttercream. Get the recipe here: https://bowlsbyalyssa.com/silky-less-sweet-lactose-free-buttercream-frosting