<p>These little thumbprint cookies are already a tradition every December in our home. This year we decided to make them with 100% buckwheat flour and they came out brilliant. Brittle, not too sweet + they have a lovely nutty flavor. We always refrigerate them for about 30 minutes before baking. This way they are easier to shape and more lovely in general. You can cover them in dark chocolate or use any jam you like, but we prefer grape jam and white chocolate. Give it a try, they are super easy to make. </p>
Whisk the buckwheat flour, cacao, baking soda and ground walnuts / pecans together in a bowl. In another bowl, whip the butter and the icing sugar with a hand-held mixer. Beat in the egg, lemon zest, rum, pinch of salt, cinnamon powder, allspice powder and ginger powder until just combined. Slowly add in the dry ingredients, mixing just until incorporated.
Wrap the cookie dough in plastic wrap and refrigerate for 30 minutes.
Preheat the oven to 165 °C / 330 °F. Shape small balls with your hands and place on the prepared baking sheets, lined with parchment paper. Place about 2 inches apart. Press a thumbprint into the center of each ball and bake for about 10 minutes. Meanwhile heat the grape jam and fill each indentation with about 1/2 teaspoon jam. Bake for another 4 minutes on 150 °C / 300 °F.
Cool the buckwheat cookies. Melt the white chocolate and place it in a piping bag. Make a pattern on each cookie. Serve or store cookies in a tightly sealed container for up to 10 days.