FIRST STEP: MAKE THE COOKIE DOUGH

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat to prevent the cookies from sticking.
2. Mix Dry Ingredients: In a medium-sized bowl, whisk together the all-purpose flour, baking powder, salt, cinnamon, and nutmeg. Set aside.
3. Cream Butter and Sugar: In a large mixing bowl, beat the softened butter and granulated sugar with an electric mixer until light and fluffy. This will take about 2-3 minutes. Make sure to scrape down the sides of the bowl as needed to ensure even mixing.
4. Add Eggs and Vanilla: Beat in the eggs, one at a time, making sure each egg is fully incorporated before adding the next. Add the vanilla extract and beat again to combine.
5. Add Eggnog: Gradually mix in the eggnog until smooth. The eggnog will add richness and moisture to the cookie dough, giving it a wonderful, creamy flavor.
6. Incorporate Dry Ingredients: Slowly add the dry ingredients into the wet ingredients, mixing until just combined. Be careful not to overmix to keep the cookies soft and tender.
7. Chill the Dough: To ensure the cookies hold their shape while baking, chill the dough in the refrigerator for at least 30 minutes.

SECOND STEP: SHAPE AND BAKE THE COOKIES

1. Shape the Dough: Using a spoon or cookie scoop, portion out about 1 ½ tablespoons of dough for each cookie. Roll into balls and place them on the prepared baking sheet, spacing them about 2 inches apart.
2. Bake the Cookies: Bake the cookies in the preheated oven for 12-15 minutes, or until the edges are lightly golden and the centers are set. The cookies should feel soft but not doughy when touched. Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

THIRD STEP: PREPARE THE TRES LECHES SOAK

1. Combine the Three Milks: In a small bowl or measuring cup, whisk together the whole milk, heavy cream, and sweetened condensed milk until fully combined. This is your tres leches soak that will infuse the cookies with their creamy, indulgent flavor.

FOURTH STEP: SOAK THE COOKIES

1. Soak the Cookies: Once the cookies have cooled completely, gently dip each cookie into the tres leches soak for about 1-2 seconds, making sure the cookie absorbs some of the liquid but doesn’t get too soggy. Alternatively, you can use a spoon to drizzle the soak over the cookies if you prefer a less intense soak.
2. Let the Cookies Absorb the Soak: Place the soaked cookies back on the wire rack or a serving plate. Let them rest for about 15-20 minutes to allow the milk mixture to soak into the cookies.

FINAL STEP: GARNISH AND SERVE

1. Garnish the Cookies: Before serving, sprinkle the cookies with a little ground cinnamon or nutmeg for a festive touch. If desired, top with a dollop of whipped cream and chopped nuts for added flavor and texture.
2. Serve: Serve these Eggnog Tres Leches Cookies chilled or at room temperature. They make a perfect treat for holiday parties, family gatherings, or as a gift for someone special.