Best-Ever Chocolate Cake

Name: Best-Ever Chocolate Cake
Cook time: 25 min
Total time: 25 min
Cuisine: European
Ingredients: Nonstick cooking spray; 3 c. all-purpose flour; 1 1/2 c. granulated sugar; 3/4 c. packed dark brown sugar; 3/4 c. unsweetened cocoa powder (not Dutch process); 1 tbsp. baking soda; 3/4 tbsp. kosher salt; 1 1/2 c. warm water; 1 1/4 c. Hellmann’s Real Mayonnaise (see tip); 2 tsp. pure vanilla extract; 1 tsp. espresso powder; 2 sticks unsalted butter, at room temp; 3 c. confectioners’ sugar; 1 1/2 tsp. pure vanilla extract; 1/4 tsp. kosher salt; 2 tbsp. milk; 1/4 c. mini chocolate chips