Preheat the oven to 350 °F (175 °C). Line two round 8" cake pans (2" tall) with parchment paper on the bottom and grease the sides of the pans.
In a large bowl, stir together the dry ingredients (sugar through salt).
2 cups granulated sugar, 1 3/4 cups Bob's Red Mill 1-to-1 Gluten-free Baking Flour, 3/4 cup (85 grams) cocoa powder, 1 1/2 teaspoons baking powder, 1 1/2 teaspoons baking soda, 1 teaspoon salt
Add the eggs, milk, oil and vanilla.
2 large eggs, 1 cup (240 ml) milk of choice, 1/2 cup (120 ml) oil, 2 teaspoons vanilla extract
Mix until combined, and then stir in the boiling water. The batter will be almost as thin as water (if using King Arthur Flour, it'll be thicker).
1 cup boiling water
Divide the batter between the two prepared pans.
Bake for 25 minutes or until a toothpick comes out with some moist crumbs, but not raw liquid.
Let cool for 5 minutes in the pans, and then turn out onto a rack to cool. Let cool completely before frosting.
Unfrosted cake layers can be wrapped in plastic wrap and stored at room temperature for 2 days or refrigerated for 3. They can also be frozen for up to 3 months.