Warm milk and buttermilk in the microwave until slightly warm but not hot. Pour in a Kitchen aide bowl. Sprinkle yeast on top. Let it sit for 5 minutes. Add sugar, salt, vanilla, zest and eggs. Attach dough hook and turn on the machine. Add the AP flour, and the bread flour, one cup at a time. After the flour is in, add the softened butter a tablespoon at a time. Let the dough kneed for a few minutes. Place the dough in an oiled bowl, cover with plastic wrap and place in the refrigerator overnight. The next day, divide dough in half.
Roll out one half of dough into a rectangle. Trim the edges to make it more exact.
