Mixing ingredients on low speed in a stand mixer and gradually increasing speed, as I indicate in the recipes, will keep the ingredients from jumping out of the bowl. On a KitchenAid stand mixer, low means number 2; medium-low, number 3; medium, number 4; medium-high, numbers 7 and 8; high, number 10. On a Cuisinart stand mixer, I use number 6 for medium. If you are using a handheld mixer, use a higher speed than specified and a longer beating time. With both methods, it’s important to scrape down the sides of the bowl to ensure that the batter on the sides gets mixed in evenly. Be sure to reach to the bottom of the bowl, especially when using the stand mixer.