Butter a 9-by-5-by-3-inch loaf pan, using about 1 tablespoon of the butter.

In a large mixing bowl (or in the bowl of a stand mixer, if you have one), combine 1 ½ cups (180 grams) of the flour with the sugar, salt, and yeast.

In a small saucepan, heat the buttermilk and 2 tablespoons of the butter over medium heat until the butter is melted and the mixture reaches about 130 degrees Fahrenheit on an instant-read thermometer (Don't worry if you don't have an instant-read thermometer. The mixture should be warm, but not hot to the touch).

Remove from the heat.

Using the stand mixer fitted with the flat beater or a hand-held electric mixer, add the warm buttermilk mixture to the flour mixture and combine well.

Add the egg and beat 1 minute more.

Add the remaining 1 3/4 cups (210 grams) flour and continue mixing for 5 minutes. If you are using a hand-held mixer, you’ll need to scrape the dough off the beaters several times.

After a few minutes, scrape it onto a board, wet your hands and, without drying them, knead the dough another minute or two. To be honest, the dough will be quite sticky and floppy at this point, so it's more flopping it on top of itself a few times than it is actually kneading. You may need to re-wet your hands to keep the dough from sticking too much.

Transfer the dough into the prepared loaf pan and spread it out to the corners.

Cover loosely with a clean dishtowel and place the pan in a warm place (like a sunny windowsill, provided the day is not too hot, or in the oven with the light turned on if your house is chilly) and let rise about 1 hour, until the dough rises above the top edge of the pan.

While the dough is rising, preheat the oven to 375ºF.

When dough has risen sufficiently, make a shallow cut lengthwise down the center of the loaf (this keeps it from pulling away from the sides of the pan as it bakes).

Melt the remaining tablespoon of butter and brush it over the loaf.

Bake in the center of the preheated oven for about 35 minutes, until the top is firm and lightly browned.

Place the pan on a wire rack and let cool 10 minutes.

Remove bread from pan and cool completely on the rack before slicing.