Preheat oven to 350 degrees F. Spray a standard loaf pan with cooking spray (I like the kind with flour in it), and set aside.
In a medium bowl, combine the flour, cocoa powder, and baking soda. Whisk to combine, and set aside.
In the bowl of a stand mixer, fitted with the paddle attachment (or a large bowl if using a hand mixer), cream together the butter and sugars until light and fluffy.
Add the eggs and mix until just combined, scraping down the sides of the bowl with a spatula as needed. Add in the yogurt and extracts and mix until combined.
With the mixer on low, slowly add in the flour and cocoa mixture. Mix until just combined, scraping down the sides as necessary. Stir in the chocolate and mint chips.
Use a spatula to push the batter into the prepared loaf pan, evening out the top as best you can. Bake for 50-60 minutes, or until a toothpick comes out mostly clean. Set aside to cool.
To prepare the glaze, combine the powdered sugar, 1 Tbsp of milk, and peppermint extract in a medium bowl or 4 cup measuring cup. Stir until combined. Add more millk if you'd like to thin the glaze out. Pour over the top of the cooled bread, and top with crushed candy cane pieces and dark chocolate chips. Slice and serve!