Step 1

Combine the whole wheat flour, bread flour and 1 1/4 cups water in a large bowl and stir with a wooden spoon to combine. Once the dough starts to form, switch to mixing with your hands, lightly kneading until there is no flour left. It will be stiff. Cover and let sit at room temperature for 2 hours.

Step 2

Whisk 2 tablespoons water with the instant yeast in a small bowl until the yeast is dissolved. Add to the bowl of a stand mixer fitted with a dough hook along with the rested dough, brown sugar, milk powder, vegetable oil and salt. Mix on low speed for 8 minutes to combine the ingredients, then increase the speed to medium-high for 8 minutes. The dough should be slightly sticky but have good gluten development, meaning it should be stretchy and slowly bounce back when pressed with your finger.

Step 3

Spray a large bowl with cooking spray and transfer the dough to the bowl. Cover and let it rise until doubled in size, 1 hour 15 minutes to 2 hours.

Step 4

Spray a 5-by-8-inch loaf pan with cooking spray. Turn the dough out onto a lightly floured work surface, flatten it gently and press into a 7-by-9-inch rectangle. Brush off any excess flour. With a shorter side of the dough facing you and starting at the opposite end, roll the dough downward tightly into a log, tucking the ends in. Pinch the seam with your fingers to seal. Transfer the dough to the prepared loaf pan, seam-side down. Cover and let rise until doubled in size, 1 hour to 1 hour 30 minutes.

Step 5

Preheat the oven to 350 degrees F. Uncover the dough and lightly spritz the top with water. Bake until the bread is an internal temperature of 210 degrees F on an instant-read thermometer and sounds hollow when tapped on top, 35 to 45 minutes.

Step 6

Immediately remove the bread from the pan and cool completely on a wire rack. The bread will keep, tightly wrapped, at room temperature for 3 days or in the freezer for up to 3 months.