Orange & Fennel Biscotti

3 cups all-purpose flour
2 tsp baking powder
1/4 cup butter, softened
1 cup granulated sugar
4 large eggs
2 tbs Triple Sec
2 tsp pure vanilla extract
2 tbs fennel seeds, lightly toasted
fine zest from one large orange
2 tbs "coffee sugar" (large granule, unrefined sugar)
Sift together flour and baking powder into a bowl. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugar until light and fluffy. Add three eggs, one at a time. Add Triple Sec and vanilla. Gradually mix in flour mixture until combined. Mix in fennel seeds and orange zest.
Turn out onto a lightly-floured surface. Divide in half. Roll halves into 12-inch logs. Flatten slightly and transfer to a Silpat-lined baking sheet. Beat remaining egg and brush over surface of dough. Sprinkle with coffee sugar. Bake 35 minutes at 325F. Transfer to a wire rack to cool for 20 minutes. Reduce oven to 300F.
Slice logs on the diagonal into about 16 pieces each. Transfer to baking sheets and bake for 8 minutes. Turn over and bake another 8 minutes. Cool completely.