Name: Chocolate Layer Cake with Vanilla Filling (Gluten-Free option)
Ingredients: Cake; 3 cups all-purpose flour (or 2-1/2 cups [300g] gluten-free flour blend with xanthan gum* plus 1/2 cup [56g] ground almond meal); 2 cups sugar; 6 tbsp cocoa powder; 2 tsp baking soda; 1 tsp salt; 3/4 cup organic olive or vegetable oil (neutral flavor); 1 large egg, optional but recommended for gluten-free version; 2 tbsp vinegar (white or apple cider); 2-1/2 tsp pure vanilla extract; 2 cups water; Filling; 3 tbsp all-purpose flour (or gluten-free flour blend); 1/2 cup milk; 1/2 cup butter or vegetable shortening, at room temperature; 1/2 cup granulated sugar; 1 tsp pure vanilla extract; Frosting; 1/2 cup butter, softened; 2/3 cup unsweetened cocoa powder; 2 to 3 cups powdered sugar, sifted; 1/3 to 1/2 cup milk, or as needed; 1 tsp pure vanilla extract