Heat the Oven & Prep the Pan: Heat your oven to 350℉. Grease and flour a 9" metal square baking pan. Preferably use butter or shortening for greasing.
Brown the Butter: To brown butter, place 1 stick of unsalted butter (1/2 cup) in a light-colored skillet or saucepan over medium heat. As the butter melts, swirl the pan occasionally to ensure even cooking. After a few minutes, the butter will begin to foam. Keep an eye on it—once the foam subsides, the butter will start to turn golden brown and emit a nutty aroma. Immediately remove the pan from heat to prevent burning. Pour the browned butter into a heatproof bowl and set aside. Mix the Dry Ingredients: In a large mixing bowl, sift together the flour, sugar, baking soda, salt, ginger, cinnamon, cloves, nutmeg, and cocoa powder. Set aside. If you do not have a sifter, whisk until thoroughly combined ensuring no lumps. Mix the Molasses with the Butter & add to Dry: To the bowl with the browned butter, add the molasses and stir well to combine. Add the butter-molasses mixture to the dry ingredients in the bowl. Mix to just moisten, but take care not to over-mix.
Add Coffee (or Water): Add coffee (or water, if using) to the batter, and gently stir to combine.
Add the Eggs and Buttermilk: Next, in a small bowl, whisk together the eggs and buttermilk. Stir the egg and buttermilk mixture into the batter until smooth and no lumps of flour remain, being careful not to overmix.If you're using candied ginger (or other mix-ins), fold it in now. Pour into Pan and Bake: Pour the batter into the prepared pan, gently smoothing the top with an offset spatula. Bake for 30 to 35 minutes, until the cake begins to pull away from the edges of the pan and a toothpick comes out clean, or with a few moistened crumbs. The cake should spring back to the touch. If you have an instant read thermometer, the internal temp of the cake should be approximately 200 to 209℉ (on the lower end preferably, for carry-over cooking). Let the Cake Cool: Once baked, remove the cake from the oven and allow to cool right in the pan. You can eat the cake straight out of the pan after 15 minutes. However, if you are adding the glaze (recommended!) or dusting with powdered sugar, allow the cake to cool completely. Make the Maple Glaze: In a small bowl, whisk together the sifted confectioner's sugar, maple syrup, cinnamon, and milk until smooth. Gently spread the mixture over the COOLED gingerbread cake with an offset spatula. Allow to set for approximately 20 minutes.