The secret to perfecting every dessert you make this season? This homemade lemon buttercream frosting. Layer cakes, cookies, cupcakes—you name it, chances are it’s going to taste better with a little bit of this citrusy frosting on top. The best part is that it’s super easy to make, and you only need four ingredients to get started. Just mix together butter, powdered sugar, lemon juice and grated lemon peel for an ultra-creamy, tart and tangy, best-you-ever-had lemon buttercream frosting.