Garlic Parsley Butter Swirl Sandwich Loaf

Steps

1. Divide the butter before you start: 25 g for the dough, 20 g for the filling and 5 g for brushing the baked loaf. Mince the garlic and chop the parsley now so the filling is ready when the dough is.
2. In a large bowl, whisk the bread flour, sugar, instant yeast, garlic powder and salt.
3. Add the warm milk, warm water and the 25 g dough portion of butter. Mix into a shaggy dough. This is about 64% hydration counting the milk as liquid, and about 1.8% salt.
4. Knead by hand 10 to 12 minutes, or 7 minutes in a stand mixer, until smooth and elastic and a small piece stretches thin without tearing.
5. Cover and let rise at about 75°F (24°C) for 60 to 90 minutes, until doubled in size.
6. Meanwhile, make the filling: stir the 20 g filling portion of butter with the garlic, parsley and black pepper into a soft paste. Grease a 9x5-inch loaf pan.
7. Turn the dough onto a lightly floured surface and roll it into a rectangle about 9 by 14 inches. Spread the garlic-parsley butter evenly over it, leaving a 1-inch strip bare on one short end.
8. Roll the dough up tightly from the filled short end, pinch the seam closed on the bare strip, and set it seam side down in the pan.
9. Cover and proof at about 75°F (24°C) for 45 to 60 minutes, until the dough crowns about 1 inch above the pan and springs back slowly when poked. Preheat the oven to 350°F (175°C) during the last 20 minutes.
10. Bake 35 to 40 minutes, until deep golden and 190°F (88°C) in the center; tent with foil if it browns too quickly.
11. Turn the loaf out onto a rack and brush the top with the remaining 5 g of butter right away to keep the crust soft.
12. Cool on the rack at least 1 hour before cutting into 12 slices.