Shortbread is a buttery, melt-in-your-mouth cookie with a sandy texture that makes the perfect companion to a hot mug of coffee or tea. However, homemade shortbread can turn out tough, dry, and crunchy, and while mastering technique is important, you can also try adding one unlikely ingredient: a hard-boiled egg yolk.

The fat-rich particles of an egg yolk act as a physical barrier between gliadin and glutenin, which come together to form gluten, the protein that makes baked goods chewy. The yolk creates soft, tender shortbread by inhibiting gluten development, but you should also avoid overworking your dough and only mix it just until it comes together.

To try this secret ingredient, use two hard-boiled egg yolks per batch of shortbread, and push the yolks through a fine sieve to create a fluffy "flour" that incorporates well into your dough, without adding wetness like fresh egg yolks would. You can also use hard-boiled yolks in baked goods like scones, biscuits, and cake doughnuts.