How to Make It
In a medium bowl, sift the buckwheat flour, baking powder, baking soda, cinnamon, nutmeg, salt and cloves. In a large bowl, using an electric mixer, beat the butter at medium speed until creamy. Add the sugar and beat until fluffy, 3 minutes. Beat in 1 egg and the honey and ginger. At low speed, beat in the dry ingredients in 3 additions, just until combined. Turn the dough out onto a work surface and pat it into a 6-inch round. Wrap in plastic and refrigerate for 4 hours or overnight.
Preheat the oven to 375°. Line 2 baking sheets with parchment paper. Turn the dough out onto a lightly floured work surface. Divide it into 6 equal pieces. Form each piece into a 6-inch-long log; if the dough is sticky, wet your hands slightly. Transfer 3 logs to each baking sheet, spacing them 3 inches apart.
In a small bowl, beat the remaining egg and brush it all over the logs. Bake for 12 to 15 minutes, until the logs are springy to the touch. Transfer to a rack to cool completely. To serve, slice the logs on the diagonal into 1/2-inch-thick cookies.