Place the ground meat in a large bowl.
Grate the onion over the bowl to collect the grated pieces and any resulting juices.
Add the garlic, paprika, salt, and pepper. Mix until evenly combined.
In a small bowl, whisk together the baking soda and sparkling water. Add to the meat mixture and mix well with your hands for roughly 5 minutes until completely combined.
Cover the bowl and refrigerate 12-24 hours to allow the flavors to blend.
Line a baking sheet with parchment. Grease the parchment lightly with sunflower or vegetable oil.
Transfer the rested mixture to a piping bag with a 3/4 inch (2 centimeter) corner snipped off.
Pipe 3 inch (7.6 centimeter) long logs of the meat mixture in rows across the parchment to make roughly 20 Ćevapi in all.
Place a large cast iron skillet over medium-high heat and add a thin layer of oil.
Once heated, transfer a few of the Ćevapi to the pan, taking care to not overcrowd.
Cook, turning occasionally, until golden brown on all sides and heated through to 165˚F (74˚C).
Transfer the cooked Ćevapi to a plate and repeat with the remaining pieces.
Serve immediately.