Preheat oven to 350℉. Cream together butter and sugar until light and fluffy. Add eggs one at a time, incorporating before adding the next. Beat in vanilla.
In a small bowl combine flour, baking powder, salt and peppercorns. Add to butter and egg mixture, beating until combined. Stir in dried cherries.
Line a large baking sheet with parchment paper. Divided dough into two. Shape each portion into a long flat log approximately 2 1/2"x 9 1/2"x1" high. Whisk egg white with a tbsp of water and brush over each log. Bake for 30 minutes, remove from oven and allow to cool for 10-15 minutes. Reduce oven temperature to 300℉. Cut each log into 3/4" slices and lay each piece flat on the baking sheet. Bake for 10 minutes, turn over each piece and bake for an additional 10 minutes.
Remove from oven and allow to cool. Melt white chocolate and drizzle over each piece.