Preheat the oven to 350 F (177 C). Lightly grease and line the bottom and two sides of a 9 x 9 inch (23 cm) cake pan with parchment paper.
In a microwave safe cup, heat water to hot and mix in the molasses until smooth and well combined.
½ cup (118 ml) molasses, ½ cup (118 ml) hot water
In a mixing bowl whisk the all purpose flour, baking soda, ground cinnamon, ground ginger, ground cloves and salt together until well combined.
1¼ cup (150 g) all purpose flour, ¾ teaspoon baking soda, 2 teaspoons ground ginger, 1 teaspoon ground cinnamon , ¼ teaspoon ground cloves, ½ teaspoon salt
In a large mixing bowl, beat the brown sugar and lemon zest together until they are the consistency of wet sand. Beat butter and lemon sugar together until light and fluffy. This takes about 2-3 minutes on medium speed.
½ cup (100 g) light brown sugar, 1 lemon, zested, 4 tablespoons (57 g) unsalted butter, room temperature
On low, beat in the egg and warm molasses water until smooth and well combined. Mix the dry ingredients into wet until just combined.
1 large egg, room temperature
Evenly pour the molasses cake batter into the prepared pan. Bake the ginger cake for 28 - 32 minutes or until a toothpick inserted into the center of the cake comes out clean or with a few moist crumbs.
Cool the pan in the pan for 10 minutes. Gently lift the molasses spice cake out of the pan using the parchment paper. Transfer to a serving plate or serve right from the pan. Top with powdered sugar, a glaze or cream cheese frosting, slice and enjoy!