This spice cake is good with lightly sweetened whipped cream; it can also be sprinkled with minced Candied Ginger.
Preheat oven to 350 degrees. In a food processor, pulse ginger until finely chopped (or chop by hand). You should have 1 cup.
In a large bowl, whisk together flour, baking soda, and salt. In another bowl, whisk together granulated sugar, molasses, and eggs until smooth. Whisk in butter and 1/3 cup hot water. Stir in flour mixture just until incorporated; stir in ginger.
Generously coat a nonstick 3-quart Bundt pan with cooking spray. Pour batter into pan; bake until a toothpick inserted in cake comes out clean, about 45 minutes.
Transfer pan to a wire rack; let cool completely, about 1 hour. Run a knife around edge of cake; then invert. Dust with confectioners' sugar before slicing.