Combine 2 cups of flour, sugar, baking powder, undissolved yeast and water in a large mixer bowl. Mix on medium speed of mixer for 1 minute. Cover with plastic wrap and set aside while preparing additional ingredients OR refrigerate overnight.
Roll basil leaves into cigar shape and thinly slice (chiffonade); chop sundried tomatoes. Add to bowl of dough along with mozzarella cheese and salt, mix to combine.
Add enough remaining flour to form a soft dough. Knead on a lightly floured surface for 6 to 8 minutes, until dough is smooth and elastic. Cover and let rest 10 minutes.
Cut dough in half. Form each half into a smooth loaf. Place in greased 8-1/2 x 4-1/2 inch loaf pan. Brush bread with olive oil. Repeat with second loaf. Cover and let rise in a warm, draft-free place for about 45 minutes, or until loaves have doubled in size.
Sprinkle with poppy seeds, if desired.
Bake in preheated 375°F oven for 25 to 30 minutes until done.