01 - Combine flour, sugar, yeast, and salt in a large mixing bowl. Slowly add warm water while mixing to form a soft, elastic dough.
02 - Knead dough on a floured surface for 5–7 minutes until smooth. Place in a lightly greased bowl, cover with plastic wrap, and let rise until doubled, about 45 minutes.
03 - Turn out risen dough onto a work surface. Divide into 24 equal portions. Flatten each and place a cube of mozzarella in the center, then pinch edges to seal tightly and roll gently into a ball.
04 - Bring water and baking soda to a gentle boil in a deep saucepan.
05 - Carefully lower bites into simmering water in batches, poaching for 30 seconds. Remove with a slotted spoon and place on a parchment-lined baking sheet.
06 - Brush tops of bites with melted butter and immediately sprinkle with coarse salt.
07 - Preheat oven to 400°F. Bake bites for 12–14 minutes until deeply golden.
08 - Allow bites to cool slightly before serving warm for best flavor and texture.