Preheat the Oven: Heat the oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream the Butter and Sugar: Beat butter and sugar until light and fluffy.
Add Vanilla and Flour: Mix in vanilla extract, then gradually add flour and salt until dough forms.
Shape the Cookies: Roll dough into 1½-inch balls, flatten slightly, and place on baking sheets.
Bake: Bake for 10-12 minutes until edges are golden. Let cookies cool completely on a wire rack.
Prepare the Ganache: Heat heavy cream and espresso in a saucepan until simmering.
Melt the Chocolate: Pour the hot cream mixture over chocolate chips. Let sit for 2 minutes, then whisk until smooth.
Add Vanilla: Stir in vanilla extract for extra flavor.
Assemble: Spoon ganache over cooled cookies and spread evenly.
Set and Serve: Let the ganache set at room temperature before serving.