First, line a cookie sheet with parchment paper or a silicone baking mat. Remember, this dough needs to chill later!
In a large bowl, using an electric mixer, beat the softened butter with both sugars until light and fluffy. Then, mix in the vanilla extract, egg, and your choice of water or brewed coffee until well combined.
Stir in the cocoa powder and the dry instant pudding mix until smooth.
In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add these dry ingredients to your wet mixture, mixing just until everything is combined. Be careful not to overmix!
Gently fold in the Valentine M&Ms and sprinkles.
Using a 2-tablespoon scoop, drop dough balls onto your prepared cookie sheet. You don't need to space them out for now. For extra charm, gently press a few M&Ms and sprinkles onto the top of each dough ball. Cover with plastic wrap and chill in the refrigerator for at least 1 hour (this is key for perfect cookies!).
Once chilled, preheat your oven to 350°F (175°C). Line another cookie sheet (or reuse the first if cooled) with parchment paper. Place the chilled dough balls about 2 inches apart. Gently flatten each cookie dough ball with the palm of your hand.
Bake for 10-14 minutes, or until the edges look set and the center just loses its glossy sheen. For best results, rotate your baking sheet halfway through. These cookies are delicious slightly underdone!
Let the warm cookies cool on the baking sheet for about 5 minutes, then carefully transfer them to a wire rack to cool completely.