Preheat oven 400 degrees F.
Combine flour, sugar, salt and cold butter in the bowl of an electric stand mixer and pulse until well combined. Mixture will look like coarse sand
In a small bowl combine 3 tablespoon milk and 1 tablespoon cold water. Add yeast and stir slightly with a wooden spoon. Rest mixture for 5 minutes.
Add remaining ¼ cup milk and the yeast mixture to the dry ingredients and blend until dough forms a ball. Allow the dough to rest 15 minutes at room temperature
Roll dough out onto a well floured surface to ¼ inch thickness, cut rounds using the large pastry tip or other small circular cutter
Cover ungreased cookie sheet with parchment paper, place dough rounds ¼ - ⅛ inch apart.
Bake crackers for 10-15 minutes checking for doneness at 10 minutes. Gently shake the cookie sheet to flip crackers for even browning, sprinkle with additional sea salt to taste and continue cooking until lightly golden browned.