1-First Step: Mix the dry ingredients Start by combining the flour, cocoa powder, and salt in a medium bowl. Stir them together well so the cocoa is evenly spread through the flour. Set the bowl aside while you work on the butter mixture. This step helps the cookie dough bake evenly and gives the cookies their even chocolate color.

2-Second Step: Cream the butter and sugar In a large bowl, beat the softened butter and granulated sugar until the mixture looks smooth and creamy, about 3 minutes. You want it light enough to blend well with the wet ingredients. This creates the base that gives these Homemade Thin Mints their tender, crisp texture.

3-Third Step: Add the egg white and extracts Beat in the egg white, vanilla extract, and peppermint extract. The dough may look a little curdled at this stage, and that is completely normal. Keep going, because it comes together once the dry ingredients are added. If you want a stronger mint flavor, you can add a little extra peppermint extract later in the coating instead of changing the dough.

4-Fourth Step: Add the dry mixture Gradually add the flour mixture in three parts, beating just until each addition is mixed in. Scrape down the sides of the bowl as needed so no dry pockets remain. Avoid overmixing, because that can make the cookies less crisp. The dough should be soft but easy to handle.

5-Fifth Step: Roll and chill the dough Divide the dough in half. Place each portion between two sheets of parchment paper and roll it to about 1/4-inch thickness. Keeping the dough between parchment makes it easier to work with and helps prevent sticking. You can stack the rolled slabs with parchment between them if you need to save space in the fridge or freezer. Refrigerate the dough slabs for at least 3 hours, or freeze them for 1 hour if you need to move faster. The dough can also be refrigerated for up to 3 days or frozen for up to 2 months, which makes these cookies great for planning ahead.

6-Sixth Step: Cut the cookies Preheat the oven to 350°F and line baking sheets with parchment paper. Remove the top layer of parchment from one dough slab, then cut out 2-inch circles. Place the cookies about 1.5 inches apart on the prepared baking sheets. Gather the scraps, reroll them, and chill the dough again before cutting more rounds. This extra chill helps the cookies keep their shape.

7-Seventh Step: Bake until firm Bake the cookies for 15 to 18 minutes, or until they feel firm to the touch. They should be set but not hard. Let them cool on the baking sheet for 5 minutes, then move them to a wire rack to cool completely. If you have a stone tray, that can help with texture. Metal sheets may brown the bottoms too quickly.

8-Eighth Step: Melt the coating For the chocolate coating, place the chopped chocolate, vegetable oil, and peppermint extract in a heatproof bowl set over a pan of simmering water. Stir until the chocolate is smooth and glossy. Using chopped bar chocolate instead of chips gives a smoother melt, which makes dipping easier. A double boiler setup helps keep the chocolate at the right texture while you work.

9-Ninth Step: Dip and set Use a fork to dip each cooled cookie into the melted chocolate. Lift it out and tap the fork gently on the side of the bowl so the excess chocolate falls off. Place the coated cookies on a parchment-lined sheet. Once all the cookies are dipped, refrigerate them for about 10 minutes until the chocolate is set.

10-Tenth Step: Serve cold Serve the cookies cold for the best snap and the cleanest mint chocolate flavor. That chilled bite is part of what makes Homemade Thin Mints so loved. If you want a firmer shell, tempering the chocolate coating can give the cookies a crisp snap.