Makes 2 oval loaves
Sprinkle dry yeast over warm water (105 - 115 F) in small bowl. Add 1 tsp honey and stir to dissolve. If using cake yeast, crumble yeast into small bowl. Stir in lukewarm water (95 F) and 1 tsp honey. Let stand until foamy, about 10 minutes.
Combine 2 cups flour, buttermilk, 3 Tbs honey, butter and salt in large bowl. Add yeast mixture and whisk until smooth, about 3 minutes. Using wooden spoon, mix in enough remaining flour 1/2 cup at a time until dough is too stiff to stir. Knead on floured surface until dough is smooth and satiny, kneading in more flour if sticky, about 10 minutes.
Grease large bowl. Add dough, turning to coat entire surface. Cover bowl with plastic. Let rise in warm draft-free area until doubled, about 1 1/2 hours.
Grease 2 baking sheets. Gently knead dough on lightly floured surface until deflated. Cut dough in half. Knead each piece into round. Pull 2 opposite sides under to form oval. Place on prepared sheets, seam side down. Cover with towel. Let rise in warm draft-free area until doubled, about 45 minutes.
Position rack in center of oven and preheat to 375 F. Bake until brown and loaves sound hollow when tapped on bottom, about 45 minutes. Immediately transfer to racks. Cool completely before slicing.