Jill O'Connor, the well-known baking genius behind the cookbook Cake, I Love You, isn't immune to the age-old problem of leaning cake layers. You've been there: You decide to make a cake for a friend's birthday, spend way too much time finding the best recipe, bake the cake itself perfectly, and botch the whole thing when your not-so-perfect slicing and re-stacking technique leaves the cake looking like the leaning tower of Pisa. By celebration time, you hate your cake.

According to Jill, the secret isn't in using any special tools: "There are lots of complicated methods for splitting one cake layer into two equal layers, involving rulers and toothpicks and dental floss or cake-splitting tools that you can't fit in your tool drawer," she says. "But the fastest and easiest (and laziest) method I know, and the one I turn to time and time again, involves a simple trick that will ensure that your cake won't be lopsided."

All you have to do is put a little notch in the side of the cake.

Of course, she's quick to remind us that you need to start with cold cake layers before you cut them. (Cold cake layers are firmer and less likely to crumble or tear when you split them.)

To use the notching technique, first place the first cake layer, bottom-side up, on a cardboard cake round. This gives the cake a nice flat surface for frosting, and eliminates the need to cut away any cake to make it level.

With a paring knife, cut a tiny (approximately 1/4-inch) triangular-shaped notch out of the side of the cake — big enough to see, but small enough to be hidden easily when the cake is frosted.

Place the cake layer on a turntable. With the paring knife, score a line halfway up the side of the cake and all the way around, to act as a guide when you begin cutting the cake in half horizontally. Place one hand on top of the cake to steady it and with the other hand, using a long serrated knife, begin slicing through the cake with a gentle sawing motion, following the line you scored into the cake, to form two even layers.

Separate the two layers. Spread the bottom layer with frosting or other filling, replace the top cake layer, carefully settling it over the filling and lining up the triangular notches to ensure the cake is level.

Matching the notches means that even if you don't slice the layers perfectly evenly, you're putting the cake back together the same way it came apart — which means a lovable flat top that's ready for frosting. Thanks, Jill.