Combine flour and baking powder and set aside.
In the bowl of your stand mixer fitted with a paddle attachment, or with a regular mixer, beat room temperature butter on medium-low speed until light and fluffy, about 3 minutes. Add confectioner's sugar, beat 1 minute, add granulated sugar, and beat until ingredients are fully incorporated. Stop and scrape sides down as needed.
Add egg yolks one at a time, mixing until each is fully incorporated. Next, add sea salt, zest, and grated cranberry.
Finally, add flour mixture in three batches, scraping sides as needed.
Turn dough out onto a lightly floured surface and divide into two. Roll each section into a long 2 inch-thick log. Wrap in parchment, tie ends, and chill an hour or more.
Preheat oven to 350 degrees F. Thoroughly mix rolling sugar ingredients in a small bowl and spread sugar into a rectangle on a large board. Remove dough roll from fridge, unwrap, and slowly press and roll into sugar mixture until the roll is well coated.
Slice dough roll into 1/4-inch slices. Place rounds on a parchment-lined rimmed baking sheet, an inch or so apart.
Bake cookies 10 - 12 minutes, or until they are set, but still pale. Cool on cookie sheet 10 minutes, then remove to a wire rack to cool completely.
Cookies will keep nicely in a sealed container for a few days, or longer if frozen, but they at their very best day-of.