Prepare Filling or Fillings of your choice; set aside. See directions below.
In stand mixer bowl, add 2 1/2 cups flour, yeast, sugar and salt; mix well. In saucepan or microwave-safe dish, heat milk, water and butter to 120-130°F (butter does not need to melt). Add milk mixture and eggs to flour mixture. Using a paddle attachment, blend on low speed for 30 seconds; beat on medium speed for 3 minutes.
Switch to dough hook attachment. Gradually stir in enough remaining flour to make a soft dough. Knead until smooth and elastic, about 5 to 8 minutes.(NOTE: For hand mixing: following above steps, mix ingredients in large mixing bowl using a wooden spoon or dough whisk. Knead on floured surface until smooth and elastic.) Place dough in lightly oiled bowl and turn to grease top. Cover; let rise until indentation remains after poking dough with finger down to second knuckle, about 1 hour.
Punch down dough. Divide into 2 equal parts. On lightly floured surface, roll each half to a 15x12-inch rectangle. Spread with Filling. Starting with longer side, roll up tightly. Pinch edges to seal. Form a circle, pinch ends to seal. Place each ring, seam side down, on greased cookie sheet. With scissors, make cuts, 1 inch apart, from outside of ring to 1 inch from center. Turn/twist each slice on its side. Cover; let rise until indentation remains after touching, about 30 minutes.
Preheat oven to 350ºF
Gently brush egg wash over tea ring. Sprinkle with pearl sugar (optional). Bake for 20 to 25 minutes until golden brown. Remove from cookie sheets; cool on wire racks.