In a large bowl, cream together the butter and sugar, beat in the egg yolk, molasses and vanilla. Whisk the dry ingredients, flour, baking soda, ginger, cinnamon, all spice and slat together in a separate bowl. Stir into the butter mixture gradually, and mix until incorporated.

Divide the dough into thirds. Make each third into a long 1" log in waxed paper. Wrap the waxed paper with plastic wrap. Store in the fridge for up to 3 days or freeze up to 3 weeks until ready to bake.

Preaheat oven to 350F. Slice each log into small 1/4" discs and press each disc into the sugar sprinkles. Place on parchment lined or ungreased cookie sheets about 1 1/2" apart. Bake for 8 min. Let cool on trays for 5 min. then move to cooling racks. When cooled place in an airtight container, keeps well for 1 week or freezes up to 1 month.