In a large mixing bowl, beat together 1/2 cup butter and granulated sugar with electric mixer until well combined and creamy. Beat in egg and vanilla until well combined.
In a separate small bowl mix together flour, baking powder, and salt until well combined. Beat into butter/sugar mixture until well combined. Wrap dough up in plastic wrap and refrigerate for 2-3 hours or until well chilled (can refrigerate overnight or up to a few days).
Preheat oven to 350 degrees F. Lightly spray baking sheets with nonstick spray or line with parchment paper or silpats.
Roll the cookie dough out on parchment paper, silpat, or waxed paper. Until about a 1/4-inch thick. Cut dough into squares about 2 1/2-inch in diameter. Reroll dough and cut until dough is used up. Cut each square in half into 2 triangles.
Place triangles on baking sheets. Bake at 350 degrees F for about 14-17 minutes or until lightly browned underneath. Cool slightly then place on wire racks to cool completely.
Place chocolate chips, Kahlua, milk, and 1 teaspoon butter in small microwave safe bowl. Microwave on half power in 30 second intervals, stirring after each interval, until smooth.
Using a fork, drizzle chocolate over cookies. Cool completely for chocolate to set (or place in refrigerator to expedite cooling).
SNAPPY TIPS: The cookie dough can be stored in the refrigerator for a few days until you’re ready to bake.SNAPPY SUBSTITUTIONS: Try any kind of Liqueur or substitute milk or use a little vanilla. You could also use Kahlua (or liqueur) of choice in the cookie dough instead of vanilla.