Preheat the oven to 375°F. Line a large baking sheet with parchment paper and lightly coat the parchment with nonstick spray.

Unroll the Pillsbury crescent dough sheet on a clean work surface. Use a rolling pin to roll the dough into a 10×12-inch rectangle.

Using a 2¼-inch round cutter, cut 24 rounds from the dough. Re-roll scraps as needed to reach 24 rounds.

Place 12 of the rounds on the prepared baking sheet, spaced about 1 inch apart. Set the remaining 12 rounds aside.

Beat the egg in a small bowl. Brush the 12 rounds on the baking sheet with some of the beaten egg; reserve the rest of the beaten egg for later.

Place one 1/8-inch slice of kielbasa in the center of each egg-brushed round.

Top each kielbasa slice with one 1/8-inch jalapeno round and 1/4 teaspoon of softened cream cheese.

Place one of the reserved dough rounds over each stacked bite. Gently press around the edges to seal.

Brush the tops of the sealed bites with the remaining beaten egg. Sprinkle each lightly with coarse sea salt. Use the tines of a small fork (dip the fork into the beaten egg if it helps prevent sticking) to press and crimp the edges and create small vent marks.

Bake in the preheated 375°F oven for 12–14 minutes, or until the popper bites are golden brown.

Remove from the oven and let cool for a few minutes before serving.