Chocolate-Filled Buns

In a large bowl, whisk together white whole-wheat flour, sugar, salt and yeast.

In a microwave-safe bowl, combine milk, water, butter and oil and heat until lukewarm. Pour mixture into the flour mixture and stir until well combined. Add egg and stir for 1 minute.

Add 2 cups bread flour to the wet mixture and stir until a soft dough forms. Scoop the mixture out onto a lightly floured surface and knead until smooth.

Place dough in a large bowl coated with cooking spray and lightly coat top of dough with cooking spray, cover and place in the refrigerator to chill overnight.

Preheat oven to 375 degrees F.

Scoop out dough onto a lightly floured work surface. Evenly divide dough into equal pieces, shaping each into a ball. Roll each piece into a 5-inch circle. Place roughly 2 teaspoons of the chopped chocolate in the center of circle. Roll up dough tightly, jelly-roll fashion and pinch the seams to seal.

Place buns, seam side down, on a baking sheet lightly coated with nonstick spray. Tuck ends under and cover with plastic wrap and repeat procedure with remaining dough and chocolate. Lightly coat the top of the dough with cooking spray to prevent sticking and cover. Let rise until puffy and almost doubled in size.

Lightly brush tops of buns with egg white. Bake until lightly browned, about 15 to 20 minutes. Remove and let cool on a wire rack.