Preheat your oven to 350°F (175°C).
Cream butter and brown sugar together until fluffy.
Add egg and vanilla, mixing well.
In another bowl, whisk together flour, cocoa powder, baking soda, and salt.
Gradually add dry ingredients to wet mixture, stirring until combined.
Stir in chocolate chips.
Scoop dough onto a baking sheet and bake for 12-15 minutes.
For the frappuccino: brew coffee and cool it.
Blend the coffee, milk, caramel syrup, and ice cubes until smooth.
Top with whipped cream and drizzle with extra caramel syrup.
Serve frappuccino with the warm cookies.