In a small saucepan over medium-low heat, gently warm the milk and cream until it reaches 110°F (40°C). Avoid overheating, as this will kill your yeast. If it gets too hot, allow it to cool down to the right temperature. Add the active dry yeast and mix to combine, letting it sit for about 5 minutes until frothy.

In a large mixing bowl, whisk together the melted butter and sugar until well combined. Then, beat in the egg along with the milk-yeast mixture until the batter is smooth and inviting.

Gradually add the all-purpose flour in two or three additions, mixing well after each addition. Ensure all the flour is incorporated for a smooth dough.

Transfer the dough to a lightly floured surface and knead until it’s completely smooth and soft, about 8-10 minutes.

Place the kneaded dough in a bowl, cover it with a towel, and let it rise in a warm spot for 1 to 1 ½ hours, or until it nearly doubles in size.

Once the dough has risen, sprinkle the chocolate chips over it. Knead the dough again, ensuring the chocolate chips are evenly distributed throughout.

Using a kitchen scale, divide the dough into either 4 or 8 equal pieces for shaping. Each piece should be rounded into small oblong loaves.

Arrange the shaped loaves on a parchment-lined baking sheet, cover with a towel, and let them rest for an additional 30 minutes to puff up.

While the loaves are resting, preheat your oven to 475°F (250°C).

Once the loaves have risen, uncover them and brush the tops and sides with the egg wash mixture. Use a sharp knife to slice a few diagonal slashes across the tops.

Bake for about 10 to 12 minutes for smaller loaves, or 12 to 14 minutes for larger loaves, until achieving a dark golden-brown finish.

Serve the Viennoise au Chocolat slightly warm or at room temperature, when the chocolate chips are still gooey.