Cream butter and sugar together. Add in eggs and sour cream, beating until smooth and creamy. Add in dry ingredients and mix until all combined. Stir in chocolate chips and peppermint extract.
Spoon batter into a well greased loaf pan. Bake in a preheated 350 degree oven for 50-55 minutes, until toothpick inserted in center comes out clean.
Let bread rest in pan for 20 minutes before removing to cool completely.
For the chocolate glaze: White bread is baking, make the chocolate glaze. (You can see detailed instructions on how to make this glaze here- it's my favorite recipe for chocolate ganache. I list just the basic steps in this recipe.)
Pour chocolate in a medium sized bowl. Set aside. Melt butter in a small saucepan over medium heat. Add in cream when butter is just about melted. Increase heat slightly and using a whisk, stir constantly, but gently. Heat until mixture just barely comes to a boil. Pour over chocolate in bowl. Stirring gently, combining the chocolate with the butter-cream mixture until it's smooth. Add in the peppermint extract and stir to combine. Let chocolate sit on the counter to cool while the bread is baking.
Once bread has cooled, drizzle spoonfuls of the glaze over the top, allowing it to drip down the sides as you'd like. I like the chocolate to be fairly cool at this point, so I spread enough on top to cover the bread, then drizzled it around so that some would go down the sides.
Top with crushed candy canes.