Soft Condensed Milk Dinner Rolls - Eggless Recipe with Sponge-and-Dough Method

I love making dinner rolls as it is a lot of fun shaping all the little balls of dough, placing them evenly in the baking pan, and watch them grow into soft and fluffy little guys - they are simply so cute! For today's recipe, I did not use egg, and also dusted bread flour on top of the dough, so the dinner rolls are light in colour and remind me of snowman, although the shape is different :D Sponge-and-dough method is used for a better texture.
Here are the ingredients you need:
Sponge:
150g (0.6 cup) milk
3g (1 tsp) dry yeast
220g (or 1.4 cup) bread flour
Bread dough:
All the sponge
100g (0.6 cup) bread flour
10g (0.8 tbsp) sugar
50g (2.6 tbsp) condensed milk
1g (or 1/3 tsp) dry yeast
60g (or 4 tbsp) milk
3g (0.5 tsp) salt
20g (1.4 tbsp) butter
Decoration:
Some bread flour
Thank you so much for watching!