In a large bowl combine 1 cup warm water, 1 envelope active dry yeast, and 1/4 cup honey. Stir, then let sit 10 minutes or until the mixture is foamy.
Stir in 3 tablespoons melted butter (cooled) and 1 teaspoon salt.
Add 1 1/2 cups whole wheat flour and most of the 2 1/4 cups bread flour, keeping a small portion of the bread flour in reserve. Mix until incorporated. Add from the reserved bread flour as needed (up to the full 2 1/4 cups total) to form a soft but slightly stiff dough.
Turn the dough onto a lightly floured surface and knead 5–7 minutes, until the dough is smooth and elastic.
Lightly grease the ball of dough, place it in a clean dry bowl, cover with plastic wrap and a kitchen towel, and let rise about 1 hour or until doubled in size.
Punch down the dough and let it rest 10 minutes.
Grease a bread pan, shape the dough to fit the pan, place it in the pan, then cover with plastic wrap and a kitchen towel. Let the dough rise again until doubled, about 45 minutes.
Preheat the oven to 375°F while the dough finishes its second rise.
Brush the top of the loaf with 2 tablespoons milk and sprinkle oats evenly over the top.
Bake at 375°F for 30–40 minutes, until the loaf is golden.
Let the loaf cool in the pan for 20 minutes, then remove it from the pan and let it cool completely before slicing.