8 tablespoons (1 stick) cool unsalted butter, cut into pieces
1/2 cup granulated sugar, plus extra for rolling
1 cup light brown sugar, packed
1/3 cup molasses (not blackstrap)
2 egg whites
Combine the flour, baking soda, and spices in a mixing bowl and set aside.
Cream the butter until smooth and fluffy in a mixer fitted with a paddle attachment (or using a hand mixer). Add the sugars and mix. Add the molasses and mix.
Add the egg whites one at a time, mixing to combine after each addition.
Add the dry ingredients in 3 batches, mixing to combine after each addition.
Heat the oven to 350 degrees F. Place some granulated sugar on a small plate.
Roll the dough into 3/4-inch balls, then roll each ball in the sugar until lightly coated.
Transfer to parchment lined cookie sheets, leaving 1-inch of space between the cookies.
Bake until browned, 10 to 12 minutes. Let cool on wire racks and store in an airtight container.