Lydia's 10-Layer Chocolate Cake

Name: Lydia's 10-Layer Chocolate Cake
Prep time: 20 min
Cook time: 18 min
Total time: 38 min
Cuisine: American
Ingredients: 2 boxes yellow cake mix ((I used Duncan Hines Butter Golden - 15.25 oz each box)); 1 1/2 cups water; 6 large eggs, room temperature; 14 tablespoons unsalted butter, softened ((or 1 stick, plus 6 tablespoons)); 4 cups granulated sugar; 2 squares unsweetened chocolate bar ((or 2 ounces)); 4 tablespoons unsweetened cocoa powder; 2 small cans evaporated milk ((10 ounces total)); 1 cup unsalted butter ((or 2 sticks of butter)); 2 teaspoons vanilla extract; 2 sprinkles cinnamon