3 Secret Ingredients That Make Key Lime Pie Taste Even Better

As citrusy as it is creamy, a slice of key lime pie is the perfect sweet treat during the summer — or any season in Florida, where it's legally classified as the state's signature pie. Traditionally made with key limes, which boast a more aromatic and distinctly tart taste than the larger Persian limes most commonly sold at the store, the uniquely flavored dessert strikes a balance between sweet and sour that's simultaneously refreshing and comforting. Plus, as far as pies go, the tangy custard filling and crumbly crust are fairly simple to prepare — although Publix's version, which features a stellar topping, is so worth trying. However, if you are making key lime pie yourself, whether for the first time or the hundredth to perfect your recipe, there are a few expert-approved ingredients worth adding to make it even more delicious.

To help you bake the best possible key lime pie, Chowhound consulted Christina Tosi, chef and founder of the award-winning Milk Bar bakery, for her advice on preparing the classic American dessert. Besides recommending that it be served frozen for the most enjoyable eating experience, Tosi shared three secret ingredients that will take a key lime pie to the next level: yogurt, milk powder, and white chocolate. Each one is added to a different part of the bake to improve the dessert's taste and texture. The resulting pie will be richer, creamier, and shouldn't suffer from a soggy bottom, every baker's biggest fear.

Many key lime pie recipes keep the ingredients simple, but that's not always for the best. In addition to the obvious key lime zest and juice, the creamy filling standardly calls for egg yolks and sweetened condensed milk. However, Tosi suggests including more dairy for an even tastier pie. Specifically, she recommends adding ¼ cup of plain yogurt to the pie's custard filling. Just as some people add sour cream to boxed cake mixes for a better bake overall, yogurt introduces more fat and moisture into the mix, resulting in a richer and creamier dessert while still preserving its signature tanginess. The improved filling ensures that each bite of pie will be velvety smooth and mouthwatering.

When it comes to the crust, key lime pie can be made with either a pastry or graham cracker base, depending on your preferences. And while there's no shame in using a store-bought pie crust, preparing one from scratch is relatively straightforward and bound to result in a more special dessert. To make your homemade crust extra delicious, Tosi proposes adding a different type of dairy into the dough: A tablespoon of milk powder, to be exact. Not only can this dry, shelf-stable product last for years without expiring when stored correctly in the pantry, but it's an easy way to pack more flavor into your pie crust without introducing extra liquid or too much additional fat — both of which could otherwise lead to textural issues in the oven.

There's no more dreaded problem facing pies than a soggy bottom. The silly-sounding phrase refers to a wet filling saturating the pie crust before it sets, causing the bottom to become unpleasantly moist and gluey. And of course, keeping the crisp crust intact ensures that each bite is as satisfying as possible. But since key lime pie is a custard-based dessert, you can't par-cook the filling as you would with fruit to prevent it from becoming a textural disaster. Fortunately, Tosi says that a little white chocolate can go a long way to help you achieve the perfect key lime pie crust.

As baker's insurance, so to speak, simply melt some chocolate down and spread it along the pie's bottom. "Paint the crust with a thin layer of white chocolate to keep the delightful zingy moisture of the filling from sogging out the butter crust below," Tosi advises.

When used in this way, the chocolate serves as a sort of sealant to reinforce the integrity of the pie's bottom. Plus, white chocolate's sweet, buttery flavor naturally complements the rich crust and contrasts nicely with the tangy custard. All in all, chef Christina Tosi's secret ingredients for key lime pie span every part of the dessert, so you can give everything from the filling to the crust a little extra oomph for a more scrumptious dessert.