Ingredients
for the cookies
1 1/2 cups flour
1/3 cup unsweetened cocoa
1/4 teaspoon salt
1/4 teaspoon baking powder
1/2 cup unsalted butter, at room temperature
1/2 cup plus 2 tablespoon sugar
1 large egg
1 teaspoon instant coffee powder
1 tablespoon Kahlua
1/2 teaspoon vanilla extract
Sanding sugar for dusting
for the caramel sauce
1/2 cup light brown sugar
4 tablespoon unsalted butter, cubed
1/4 cup buttermilk
1 tablespoon bourbon
1/2 teaspoon vanilla extract
1 teaspoon of sea salt
Directions
For the cookies, whisk together flour, cocoa, salt, and baking powder in a medium bowl. Beat butter in a large mixer bowl at medium speed until creamy; add sugar. Beat in egg, instant coffee, Kahlua, and vanilla until combined. Reduce speed to low; gradually add flour mixture and beat just until incorporated. Wrap dough with plastic and chill in the refrigerator for at least one hour or up to overnight.
Preheat oven to 350F and line two baking sheets with silpat or parchment paper. Divide the dough into 2 sections; working with one section at a time, roll dough out to 1/8-inch thickness on a lightly floured board. Use a 2-inch rectangle cutter to cut into rectangles (or cut your own rectangles with a pastry wheel).
Repeat with remaining dough, re-rolling scraps as needed, until you have 52 rectangles (brush off excess flour, though it disappears once baked). Sprinkle half the rectangles with sanding sugar (these will be your tops), and bake for 8 minutes, until cookies are slightly puffed and edges are firm. Cool for 2 minutes on baking sheets, then transfer to a wire rack to cool completely.
For the sauce, combine brown sugar, butter, and heavy cream in a heavy saucepan. Bring to a boil over medium heat, stirring constantly until butter has melted completely. Reduce heat to low and simmer 5 minutes, stirring occasionally. Remove from heat and stir in vanilla, bourbon and sea salt until smooth. Pour sauce into a small jar to cool. Sauce will cool as it thickens; chill in the refrigerator for 1 hour before assembling cookies.
To assemble, spread caramel sauce on plain cookies and top with remaining cookies. Store leftover cookies in an airtight container in the refrigerator; bring to room temperature before serving. Store leftover caramel sauce in the refrigerator up to 2 weeks. Warm briefly before serving.
