If you’ve roasted and prepped your sweet potato ahead of time – I usually have mine ready the day before – then you’ll need to warm the mashed potato in the microwave for a bit as they can’t be cold.  Warm in 30 second increments, stirring in between, until warm to the touch but not hot.  As you’re doing this, fill the bowl of your electric mixer with hot water and leave it for a couple of minutes before pouring it out so that the bowl isn’t cold when you proof the yeast.

To proof the yeast, whisk the warm milk, yeast and 2 tablespoons of honey together in the warm bowl of your electric mixer, cover it with a kitchen towel and leave this mix to sit for 5 minutes.  After 5 minutes, the mix should be obviously bubbling.

Add the remaining honey (70 grams), eggs, softened butter, salt, warm mashed sweet potato and about 1 cup of bread flour (from your premeasured bowl) to the yeast mixture.  Use the paddle attachment and mix on low for 1 minute, then stop the mixer, scrape down the sides of the bowl, add in all of the remaining flour and mix on low for another minute until it all starts to come together.  Beat on medium speed for 3 minutes until the dough has pulled away from the sides of the bowl and the mix looks like it could form a ball.  If it seems too wet, mix in 1 more tablespoon of flour.  For the batches that I’ve made so far, I’ve needed either 1 or 2 tablespoons to deal with the moisture.  Scrape off the paddle attachment and switch to a dough hook.  Beat/knead the dough on low for 5 full minutes.  If the dough becomes too sticky as it’s being kneaded then sprinkle in a titch more flour 1 teaspoon at a time.  After kneading, the dough should feel soft and smooth and when poked, if it slowly bounces back, then it’s ready to rise.

Lightly spray or grease a large bowl with oil.  Give the dough ball a roll in it so that it won’t stick to the sides, cover the bowl with plastic wrap and leave to rise in a warm corner for 1 to 2 hours.  I use the proofing setting on my oven and after an hour it was doubled in size – doubling may take longer on a counter.  Lightly spray a 9 x 13 casserole dish.

When the dough is ready, punch it down to release the air bubbles, weigh it, and divide it (using a sharp knife) into 20 equal portions – mine worked out to be 70 to 75 grams each.  Roll and tuck each piece into a smooth ball – I hold it in the palm of one hand and use my fingers to tuck and turn so that one side comes out perfect.  Place in your prepared casserole dish in a 4 x 5 grid, with the perfect side of each piece facing up.  This dough is very easy to work with and the process to form 20 buns is really rather quick.  Cover the dish with plastic wrap and allow to rise until puffy, 30 to 45 minutes.

Preheat the oven to 350 and remove the plastic wrap.  Bake for about 30 minutes (mine all seem to take 35 minutes, the buns are very dense!), until an instant thermometer comes out of a middle bun at 190 degrees.  At 20 minutes, place a loose sheet of foil over the buns so that they don’t get too brown on top.  Remove the buns from the oven and if you’re serving them straight away, immediately and evenly brush them all with the melted butter and sprinkle generously with the flaky sea salt.  Sally suggests leaving the buns to cool for about 15 minutes before serving to increase the flavor.

If you’re making these ahead, I’ve had great success with freezing them (baked) but timing helps a lot.  Leave the buns to rest in the hot casserole dish for 10 minutes – do not brush on melted butter or add salt, then quickly and carefully flip them out onto your hand and then immediately onto a rack to cool completely.  They should all stay together in a perfect rectangle if you’re ready to maneuver.  As soon as they’re cool, wrap tightly in plastic wrap and then place in a extra large freezer bag before putting in the freezer.  On serving day, take them out of the freezer a couple of hours before and open up the freezer bag.  Preheat the oven to 250 or so, lightly spray or butter the casserole that the buns were baked in, cover them with foil again and leave to warm in the oven for about 20 minutes.  Once the buns are gently warmed though, brush on the melted butter, sprinkle with the flaky salt and serve them up.  Everyone who’s tried these has gone crazy over them!  So worth the effort!