Special equipment: stainless steel ladle with a 4-ounce (3 1/2-inch diameter) well, metal chopsticks, hotteok press (see Cook’s Note), silicone baking mat, 1-to-3-inch cookie cutters in any shape, ice pop sticks
Line a sheet tray with a silicone baking mat and lay down 1 ice pop stick in the center. Set aside.
Set a 4-ounce ladle over low heat about 2 inches above the flame and add the sugar. Stir with the chopsticks, swirling constantly until the sugar dissolves and turns pale light yellow (it should be fragrant like caramel and resemble diluted honey), about 2 minutes.
Stir in the baking soda and whisk vigorously for 5 seconds, still working 2 inches above the flame, and remove from the heat. Continue whisking until the baking soda is completely dissolved and the sugar doubles in volume, becomes frothy and turns light caramel color, about 10 seconds.
Pour the sugar immediately onto the tip of the ice pop stick on the silicone mat, scraping down with a rubber spatula. Keep a nice round shape as you pour as this will ensure the candy is pressed in an even circle. Quickly and lightly press down with hotteok press until the candy is about 3 1/2 inches in diameter, 3 to 5 seconds. As the candy begins to harden, gently lift the hotteok press and immediately stamp with a cookie cutter, making sure not to press all the way through, 5 to 10 seconds. Remove the cookie cutter and let the ppopgi cool until hardened, 2 to 3 minutes. If making more ppopgi, rinse the tools in hot water and dry completely before making the next batch.
A hotteok press is a round, stainless-steel plated, hand-held presser that is traditionally used for hotteok, a Korean sweet doughy pancake, but is also ideal for dalgona candy.