Scrub and halve a medium sweet potato. Steam for 15–20 minutes until completely tender. Cool, scoop out the flesh, and mash lightly. Measure 160g (¾ cup).
3/4 c mashed purple sweet potato (about 1 medium potato)
In a large bowl, combine warm milk, cooled and mashed sweet potato, honey, and yeast. Stir to combine.
3/4 c warm milk (whole or 2%), 1 tbsp honey, 2 tsp active dry yeast, 3 tbsp melted butter or neutral oil
Add flour and salt. Mix until a soft dough forms. If dough is too wet, add flour one handful at a time. If dough is too dry, add water one tablespoon at a time.
3 c all-purpose flour, 1/2 tsp salt
Cover the bowl and let rise in a warm place until nearly doubled, about 1 hour.
Turn the dough out onto a countertop and divide into 4 equal pieces. Shape each into a small log the width of your loaf pan.
Place the four pieces side by side in a buttered 9x5-inch loaf pan. Cover and let rise until level with the top of the pan, 30–45 minutes.
Preheat oven to 425°F (218°C). Brush the top of the loaf with beaten egg.
1 egg, beaten
Bake 20–25 minutes, until golden brown and sounds hollow when tapped.
Cool in the pan for 10 minutes, then transfer to a wire rack. Cool completely before slicing for best texture.