Preheat the oven to 375°F (190°C). Line a baking sheet with a Silpat or parchment paper; if using parchment, lightly spray it with oil to prevent sticking.
In a small bowl, combine the 1/4 teaspoon ground cinnamon and 1 tablespoon granulated sugar. Set this cinnamon-sugar mixture aside.
In a medium bowl, whisk together 1 cup flour, 2 teaspoons baking powder, and 3/4 teaspoon kosher salt.
Add 1 cup non-fat Greek yogurt to the dry ingredients. Mix with a fork or spatula until the mixture comes together and looks like small crumbles.
Lightly dust a work surface with flour. Turn the dough out onto the surface and knead it a few times—about 15 turns—until the dough is tacky but not sticky (it should not leave dough on your hands when you pull away).
Divide the dough into 4 equal pieces and shape each piece into a ball.
Roll each ball into a rope about 7 inches long and roughly 3/4 inch thick. Press each rope flat lengthwise.
Beat the 1 large egg white or whole egg. Very lightly brush the flattened surface of each rope with the beaten egg (use a minimal amount so the dough does not become wet).
Divide the cinnamon-sugar mixture into 4 equal portions. For each flattened rope, sprinkle about half of one portion over the surface, then evenly distribute 1 tablespoon mini semi-sweet chocolate chips divided among the 4 ropes (about one-quarter of the tablespoon per rope). Press the chips lightly into the dough.
Fold the long edges of each rope up and over to enclose the filling, pinch the seam closed, then join and press the ends together to form a bagel shape. Place each formed bagel seam-side down on the prepared baking sheet.
Brush the tops of the bagels lightly with the remaining beaten egg and sprinkle each with the remaining half of its cinnamon-sugar portion.
Bake on the top oven rack for 25–28 minutes, rotating the baking sheet halfway through baking for even browning. Remove from the oven and let the bagels cool on the sheet for at least 15 minutes before cutting.