Preheat the oven to 375℉ and line a baking sheet with parchment paper.
In an electric mixer, cream sugar and butter. Add vanilla and egg, mix together. Add flour, salt, baking soda, and milk, mix again. Add chopped pecans and stir to combine.
Use a small cookie scoop to get even-sized cookies (about 1-1 ½ tablespoons). Roll the cookie dough into a ball in your hands and place 1" apart on the baking sheet.
Bake in the oven for 11-12 minutes until the tops of the cookies spring back when lightly touched. Let cool on a wire rack.
Caramel Drizzle
While they bake, add ¼ cup of white granulated sugar at a time to a small saucepan over the stove. Cook until each addition is fully melted and a golden color. Slowly add 2 tablespoons of butter at a time to the saucepan while continuing to stir.
Remove from heat and add heavy cream and salt. Continue stirring until combined. Let cool to room temperature or place it in the fridge for 15-20 minutes to cool down.
Add caramel to a squeeze bottle or icing bag.
Chocolate Drizzle
Melt the bittersweet baking chocolate in a small dish. Add half of the chocolate to a squeeze bottle or icing bag and set aside. Dip each cooled cookie bottom in the small dish of melted chocolate and place them on a wire rack or wax paper to set.
Drizzle the top of each cookie with melted chocolate, followed by caramel drizzle. Sprinkle chopped pecans on top. If needed, place the cookies in the fridge to let the chocolate set.
Notes
For the chocolate drizzle, baking chocolate squares are used to get a thinner melted chocolate. Chocolate chips have a stabilizer that prevents melting into a thin liquid. Chips can still be used, but they will have a thicker drizzle.