Servings: makes 24 to 30 pieces (or 12 to 15 paired shortbread cookies)
1 cup all purpose flour
1 cup rice flour (Mochiko brand, from Asian groceries)
1 Tablespoon instant coffee powder
¼ teaspoon salt
1 cup unsalted butter, room temperature
½ cup granulated sugar
2 Tablespoons vanilla sugar *
1 teaspoon vanilla extract
1 Tablespoon brewed coffee (use leftovers)
1 Tablespoon granulated sugar, for sprinkling on cookie (optional)
¾ cup Dulce de Leche, for filling (recipe follows )
Dulce de Leche
* Inspired by @80breakfasts
1 can ( 14 ounces) sweetened condensed milk
Instructions
Remove paper labels from can.
Take a large stock pot, filled with water. Place the can of condensed milk. Water should cover the can.
Over medium high heat, cook the condensed milk can for 3 hours on a stove top. If using a slow cooker like I did ~ slow cook condensed milk on HIGH settings, for 4 hours.
When cooking time is over, turn off heat and leave the can to slowly get to room temperature. Then when cooled, refrigerate condensed milk “dulce de leche” for 6 hours or overnight. Set aside till shortbread cookies are baked and cooked to assemble sandwich.Whisk flours, coffee powder, salt in a bowl. Set aside.
In a stand mixer, cream together the butter, sugar, vanilla and brewed coffee till light and fluffy, for about 5 minutes. Turn off mixer and scrape the sides of the bowl.
Add the dry ingredients by hand and blend well till all ingredients are incorporated.
Turn out the dough on a plastic wrap and seal well. Refrigerate for at least 6 hours or overnight. I personally prefer to keep the dough overnight, so it firms up.
The next day,pre-grease and line the cookie sheets with parchment paper.
Preheat the oven to 325 F degrees.
On a lightly floured surface of your counter, place the dough and dust the top with a little flour. With a lightly floured rolling pin, gently roll the dough to ¼ inch thick cookies.
Using a round cookie cutter, cut the dough into 2-inch diameter circles. Place cookies on baking sheet, leaving a space of 1 inch apart. Prick the centers with a fork. Be sure to make an even number of cookies for you to pair up with the filling.
Sprinkle the top of cookies with granulated sugar. Bake at 325 F degrees for 15 to 17 minutes or till edges are light gold . Cool cookies on rack thoroughly before placing the Dulce de Leche filling. This should take at least 35 to 45 minutes to cool.
To fill & assemble cookies : Spread a teaspoon of dulce de leche on each shortbread cookie. Cover the caramel cream-filled cookie with another shortbread. Store in tight containers. Freeze. If kept in air tight plastic resealable bags or containers, these shortbread cookies can last for 2 to 3 weeks.
Recipe by LoveFeast Table at http://lovefeasttable.com/blog/mocha-shortbread-with-dulce-de-leche/