This French classic proves that it's hip to be square - or rectangular, at least! This particular loaf is sometimes referred to as a Pullman Loaf after its prominence in the compact kitchens of the Pullman railway cars.

• 700g (~5 cups) bread flour
• 470g (~2 cups) water, warmed to 115°F (45°C)
• 1 tbsp sugar
• 1 tbsp active dry yeast
• 2 tsp salt
• 5 tbsp butter, softened

In the bowl of a stand mixer, combine water, sugar, yeast, 1 tbsp butter, and half of the flour. Mix by hand until blended. Attach dough hook to mixer. On the #2 speed, slowly add remaining flour and salt. Knead 5 to 8 minutes then add remaining butter in small pieces, continuing to knead until completely incorporated. The dough will be sticky.

Remove bowl from mixer, cover with plastic wrap, and allow to rise in a warm place until tripled in bulk, 2 to 3 hours. Punch down and let rise again 1½ to 2 hours.

Shape the dough into a long loaf. Grease the pain de mie pan and lid with butter. Press the dough into the bottom of the pan, cover with plastic wrap, and allow to rise again, until about ½ inch (1.25cm) from the top of the pan. Attach the lid and allow to rise another 10 minutes while the oven preheats to 375°F (190°C).

Bake for 25 minutes. Remove from the oven and carefully remove the lid. Return to the oven and bake for an additional 10 minutes. Internal temperature should reach about 190°F (90°C). Remove the bread from the pan and allow to cool completely on a rack.