1 cup (140 g) unbleached all-purpose flour
1 tsp (5 ml) baking powder
½ cup (115 g) unsalted butter, softened
½ cup (105 g) sugar
1 egg yolk
½ tsp (2.5 ml) vanilla extract
1 cup (250 ml) milk caramel spread (dulce de leche)
½ cup (35 g) grated coconut
In a bowl, combine the flour and baking powder. Set aside.
In another bowl, cream the butter and sugar with an electric mixer. Add the egg yolk and vanilla extract, and beat until smooth.
With a wooden spoon, stir in the dry ingredients. Shape the dough into a disc and cover with plastic wrap. Refrigerate for 30 minutes.
With the rack in the middle position, preheat the oven to 350°F (180°C). Line two baking sheets with parchment paper or silicone mats.
On a floured work surface, roll out the dough to a thickness of about inch (3 mm). Cut out 18 cookies using a round cookie cutter about 2 ½ inches (6 cm) in diameter.
Place the cookies on the baking sheets. 5 Bake, one sheet at a time, for about 12 minutes or until the cookies start to turn lightly golden brown. Let cool completely.
For each sandwich cookie, spread 1 tbsp (15 ml) of dulce de leche on the underside of two cookies and insert another cookie between the two layers of dulce de leche.
Spread the remaining dulce de leche around the sides of the sandwich and roll the sides in the coconut.
NOTE Milk caramel spread (dulce de leche) is sold by the jar in grocery stores, in the jam section.