Preheat your oven to 350 degrees. Grease a 8x8 square casserole dish, and line with parchment paper by making a sling with paper hanging over 2 sides. Lightly spray the paper with non-stick spray.

Make the brownie layer: In a small saucepan, melt chocolate and butter. Whisk until smooth, add in instant coffee granules and sugar. Set aside to cool.

Once cooled, stir in vanilla and eggs. Whisk until smooth, then add in flour and salt. Pour into prepared dish.

Bake for 22-25 minutes or until toothpick comes out clean. Remove from oven and let cool another 10 minutes. Remove brownie layer from the pan and completely cool.

Make the peppermint layer: with an electric mixer, whip butter, powdered sugar, milk, and peppermint extract until light and fluffy. Evenly spread cream over the brownie layer and place inside the refrigerator. Cool for an hour, or until cream is firm and cold.

Make the chocolate ganache: microwave chocolate and butter in 30 second intervals. Continue to stir until completely melted. Dissolve coffee granules into 1 tbsp hot water, and add to chocolate. While warm, spread the chocolate evenly over the peppermint layer. Sprinkle with crushed candy canes (if using). Refrigerate until chocolate layer is firm (approximately 1 hour), and cut into small squares.

Brownies should be kept in the fridge and are best served cold.