Heat oven to 350°F. Grease and flour two 9-inch round baking pans. Stir together the ingredients of the jar. Add eggs, milk, oil and vanilla; beat on medium speed of mixer 2 minutes. Stir in boiling water (batter will be thin). Pour batter into prepared pans. Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean.
Chocolate Cake Mix in a Jar https://thatrecipe.com/blog/cake-mix-in-a-jar/