How to Make It
Using an electric mixer, beat cream cheese until smooth and fluffy, about 2 minutes. Add scallions, several grinds black pepper, and ¼ teaspoon of the salt. Beat until fully incorporated, scraping down sides of the bowl as necessary.
Place scant tablespoon-sized scoops of the cream cheese onto a parchment-lined baking sheet and freeze until solid, about 1 hour.
Preheat oven to 425°F. Divide the dough into 16 equal pieces. Flatten each piece to a 3-inch disk and place a frozen cream cheese ball in the center. Wrap the dough around the cream cheese, pinching to seal, and roll into a smooth ball. Place seam-side down on the baking sheet. Brush with beaten egg.
In a small bowl, combine the sesame seeds, garlic, onion, poppy seeds, remaining 2 teaspoons salt and ¼ teaspoon black pepper. Divide evenly among the tops of the bagels. Bake, rotating baking sheet halfway through, until golden brown, 18 to 20 minutes.
Serve warm or at room temperature.