Preheat oven to 350-degrees. Line a baking sheet with parchment paper; set aside.
In medium bowl, measure out the flour, baking powder, and salt; set aside.
In a big bowl, beat together the butter and sugar until light and fluffy. Add the eggs and peppermint extract. Slowly stir in the dry mix until just incorporated, then add the white chocolate chips.
Divide the dough in half on the prepared baking sheet. Form each into a log about 4 inches wide and 10 inches long; make sure there is space between the two logs, as they'll grow in the oven.
Bake about 25 minutes, until the biscotti is lightly browned. Remove the baking sheet, but be sure to leave the oven on.
Let the biscotti cool for 10 minutes. Use a large knife, such as a bread knife, to diagonally slice the logs 1/2-inch apart. Use a straight-down motion to cut; don't saw.
Arrange the biscotti spaced out on the baking sheet. Stand them up if possible, or lay them on their sides. Bake for another 25 minutes, flipping them over halfway if necessary, to equally crisp both sides.
Cool completely on the baking sheet. Crush the candy canes.
Melt the white chocolate on the stovetop or in the microwave; if necessary, stir in a drizzle of coconut oil or vegetable oil to make the chocolate loose enough to dribble.
Drizzle the chocolate all over the biscotti, then immediately sprinkle peppermint chunks over them. Let them set for a few hours at room temperature or in the fridge.
Store in an airtight container as long as a few weeks.
OM NOM NOM!