Whisk together the flour, salt and cocoa powder. Set aside. In a large mixing bowl combine the cream cheese, butter and sugars. Beat on medium-high until the mixture is fluffy, about 3 minutes. Scrape down the sides and bottom of the bowl and blend again.

Make a small well in the center of the mixture. Add the egg yolk, vanilla, peppermint extract and espresso powder. Mix gently to dissolve the espresso powder. Blend with the mixer until incorporated.

Add the flour mixture in 3 additions, scraping down the sides of the bowl as needed. Fold a few times with a spatula to ensure there are no dry pockets of flour remaining. The mixture should be thick.

Pour the coarse sugar into a shallow bowl. Roll the dough into 1 1/2 tablespoon balls about 24g each. (A heaping small cookie scoop works well.) Roll each dough ball in the coarse sugar and place on the cool prepared cookie sheet about 2-inches apart. Continue until the cookie sheet is filled.

Using a 1/2 teaspoon measuring spoon press down on the center of the dough balls to create a well. Bake for 10 to 12 minutes or until the bottoms are just set. Try not to over bake the cookies.

Remove from the oven. If the center of the cookies have filled in during baking, use the 1/2 teaspoon spoon to press down on the center of the warm cookies to create a deeper well if desired.

Remove to a rack to cool. Repeat with the remaining cookie dough ensuring the cookie sheet is cool before adding the dough balls.

Heat the cream and corn syrup in a small saucepan over medium-high heat until simmering. Remove from the heat. Add the chopped chocolate and peppermint extract and stir. Cover with a lid and set aside for 5 minutes. Stir until all chocolate is melted. Taste and add a few more drops of peppermint extract as desired.

Fill each cookie with 1 teaspoon of ganache. Immediately sprinkle with crushed candy canes. Allow the ganache to set before storing in layers separated by wax paper in an airtight container.