Make your standard yeasted challah dough. After the dough has risen overnight in the refrigerator, roll it out on your counter into a rectangle, approximately 14 by 10 inches, with a short end facing you. Lift rectangle onto a parchment-lined baking sheet.

Spread a 4-inch wide strip of pastry filling, perhaps poppy seed or almond (Solo brand has many varieties), down the length of the dough. With a pizza wheel, cut an equal number of angled strips on both sides of the filling from top to bottom of dough, from the outer edge to within a half-inch of the filling. Fold the strips over the filling, alternating one side and then the other, until all have been folded. Pinch and tuck the short ends of dough under the pastry and cover lightly with plastic wrap.

Let rise for 30 minutes at room temperature. Preheat oven to 350 degrees, brush top of dough with an egg wash and sprinkle with sugar. Bake for 30 minutes.