In the bowl of a stand mixer fitted with the paddle attachment, beat bread flour, sugar, yeast, and salt at low speed until combined. Add warm milk; beat until a dough ball forms. Add egg, melted butter, and honey; beat until well combined.
Switch to the dough hook attachment. Beat at low speed until dough is smooth and elastic and passes the windowpane test (see page 113), 12 to 15 minutes. Add dates and pecans; beat until well combined.
Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 1 to 1½ hours.
Spray a 9×5-inch loaf pan with baking spray with flour. Line pan with parchment paper, letting excess extend over sides of pan.
Turn out dough onto a lightly floured surface. Gently pat dough into a 12×9-inch rectangle. Starting with one short side, roll up dough into a log, pressing seam to seal. Place log, seam side down, in prepared pan. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 1 to 1½ hours.
Preheat oven to 350°F (180°C).
Brush egg white onto dough.
Bake until top is golden brown and an instant-read thermometer inserted in center registers 200°F (93°C), 45 to 50 minutes, loosely covering with foil after 25 minutes of baking to prevent excess browning. Let cool in pan for10 minutes. Using excess parchment as handles, remove from pan, and let cool completely on a wire rack. Store in an airtight container for up to 3 days.