Preheat the oven to 350°F. In a small bowl, combine the flour, baking soda, spices, and salt. Set aside.
2 cups all purpose flour, 1 teaspoon baking soda, 2 teaspoons ground ginger, 1½ teaspoons cinnamon, ¼ teaspoon nutmeg, ¼ teaspoon ground clove
In a standing mixer with a paddle attachment or in a large mixing bowl with a hand mixer, beat the butter and brown sugar on medium high speed for 1 to 2 minutes until pale and fluffy.
½ cup unsalted butter, ⅓ cup packed light brown sugar
Add the egg and vanilla to the bowl. Beat on medium speed for 1 minute, scrape down the sides and bottom of the bowl, then return to medium speed for about 30 seconds.
1 large egg, 1 teaspoon vanilla extract
Add the molasses and the dry ingredients. Mix for about 30 seconds until the dry ingredients are just incorporated. With the mixer on low speed, slowly add the hot water. Mix until the ingredients are combined and the batter consistency is even. Scrape down the sides and bottom of the bowl and mix for about 20 to 30 seconds. Pour the batter into the prepared pan.
¾ cup unsulphered molasses, ¾ cup boiling water
Bake in a preheated 350°F oven for 35 to 45 minutes until a toothpick inserted in the center comes out mostly clean (a few crumbs are fine!). If the edges of your cake start to darken dramatically but the center is still wet, cover the edges with aluminum foil.
After baking, let the cake cool for 10 to 15 minutes. Run a knife along the sides of the pan. Place the serving dish - or a parchment covered plate if you plan to transfer the cake before serving - on top of the cake. Flip over and let sit for 2 to 3 minutes before lifting the pan.
Suggest to serve warm with fresh whipped cream or ice cream! If baking in advance, heat in the microwave or oven for a few minutes before serving or serve at room temperature, it's delicious either way.