Sprinkle yeast over warm water in a large bowl (I used the bowl of my mixer with the dough hook). Let stand until foamy, about 5 minutes. Whisk in 2 teaspoons malt syrup until smooth. Add in the flour, coarse salt, buttermilk, and 3 tablespoons butter. Mix the dough until combined.

Turn the dough out onto a lightly floured bread board (or clean counter) and knead until smooth and elastic Shape the dough into a ball.

Place the dough right side down into a large, buttered (or oiled) bowl, then, turn right-side-up.

Cover with plastic wrap and allow to rise for about 1 hour. Remove the dough after the rising

Preheat oven to 400 degrees. Punch down dough.

Turn dough out onto a well-floured work surface. With floured hands, roll dough into a thick log. Cut into 12 equal pieces (my pieces weighed about 50 g each).

Brush a 9-by-9-inch baking pan with butter or line with parchment paper and then brush with butter.

One at a time, flatten each piece of dough, then fold edges toward the center, pressing to secure, until a smooth ball forms. Place dough balls in prepared baking pan, smooth side up (you should have 3 rows of 4 in a 9×9 pan). Cover loosely with plastic wrap, and let rise in a warm place until doubled in bulk, 30 to 40 minutes. (Alternatively, refrigerate, at least 4 hours and up to 1 day.)

Preheat oven to 400 degrees. Remove plastic wrap; brush rolls with butter.

Whisk together remaining 1 tablespoon each malt syrup and butter in a small bowl; brush over top of dough (I added a little bit of water, as the malt syrup was too thick). Bake until puffed and golden brown, 15 to 18 minutes. (If tops are browning too quickly, tent with foil.) Sprinkle with flaky salt. Serve warm.