Start by melting 4 ounces of semisweet chocolate and ½ cup of unsalted butter in a heatproof bowl over simmering water, stirring until smooth. In a separate bowl, whisk together ½ cup of cocoa powder, 1 cup of all-purpose flour, 1 teaspoon of ground cinnamon, 1 teaspoon of ground ginger, ¼ teaspoon of ground nutmeg, and ¼ teaspoon of ground cloves.

In another bowl, beat 2 eggs with 1 cup of light brown sugar and ¼ cup of molasses, then stir in the melted chocolate mixture before blending the dry ingredients and ½ cup of chopped crystallized ginger until fully combined.

Preheat your oven to 350°F (175°C) and lightly grease a 9x9 inch baking pan. Pour the gingerbread brownie batter into the prepared pan, spreading it evenly. Bake for 30 minutes until the top appears set and a toothpick comes out with a few moist crumbs.

Once baked, place the pan on a wire rack and let the brownies cool completely in the pan for at least 30 minutes.

While the brownies cool, prepare the Eggnog Cream Cheese Frosting by beating 8 ounces of softened cream cheese and ¼ cup of unsalted butter until smooth. Gradually add in 2 cups of powdered sugar, along with ¼ cup of eggnog, 1 teaspoon of vanilla extract, and a pinch of ground nutmeg.

Once cooled, gently remove the brownies from the pan and place them on a serving platter. Spread the frosting evenly over the top and dust with ground cinnamon before cutting into squares.

Store the frosted gingerbread brownies in an airtight container for up to 5 days or refrigerate for a firmer texture.