Whisk together flour, espresso and salt. Set aside.

In a stand mixer, cream butter and sugar. Beat in vanilla. Slowly add dry ingredients, mixing until just combined. If using a cookie cutter, pat into a disk, cover with plastic wrap and refrigerate at least 30 minutes. If utilizing the slice and bake method, roll into a log, cover with plastic wrap and freeze until firm.

Preheat oven to 350F. Line baking sheets with parchment paper. After dough has chilled, roll to ⅛ inch thickness and use small cutter to make desired shape. Repeat with scraps. Or, slice log into ⅛ inch thick slices. Place on baking sheet and bake for 8-10 minutes. Let cool on pan for 2 minutes before removing to a wire rack to cool completely.

For the ganache: bring cream to a simmer. Pour over chocolate in a small bowl and stir until smooth. Cover and refrigerate until cooled. Spread onto bottom of half the cookies, top with remaining cookies.