Preheat the oven to 375 degrees F. In a medium bowl, stir together the flour, baking powder, salt, and spices. Set aside.
Using a hand or stand mixer, cream together the butter and sugar. Mix in egg, yolk, vanilla, molasses, and condensed milk until combined. Stir in the dry ingredients, mixing until fully combined. The dough will be soft. I put it in the freezer for 10 minutes to firm up but that step is really optional.
Use a spoon, cookie/ice cream scoop, or your fingers to drop about 2 tablespoons of dough into the reserved 1/3 cup of sugar. Toss the dough with your fingers to coat it in sugar. Once it is coated, you can handle it better. Roll between your two palms to form a ball, then place onto a greased or silicone mat/parchment paper lined baking sheet. Leave 2-3 inches between the balls.
Bake for 10-12 minutes. This leaves them slightly under baked so they stay chewy. Once they flatten and the centers puff up, remove them from the oven. Let cool on baking sheet for 3 minutes before moving to a cooling rack. The cookies will flatten as they cool, but should remain soft and slightly chewy.