How to Make It
Preheat oven to 350°F. Grease a 9- x 5-inch loaf pan with baking spray with flour. Beat sugar and butter with a stand mixer fitted with a paddle attachment on medium-high speed until fluffy, about 3 minutes. Add eggs 1 at a time, beating well after each addition.
Stir together flour, baking powder, and salt in a bowl; add to butter mixture alternately with milk, beginning and ending with flour mixture, beating on medium speed until just combined. Pour half of the batter into a separate bowl. Add molasses, cinnamon, cloves, and ginger to 1 of the bowls of batter, stirring until smooth. (You will have 1 bowl of dark batter and 1 bowl of light batter.)
Drop batters by tablespoonfuls into prepared pan, alternating between dark and light batters.
Bake in preheated oven until a wooden pick inserted in center of loaf comes out clean, 45 to 50 minutes. Let cool in pan 10 minutes. Remove loaf from pan; let cool completely on a wire rack, about 1 hour.