Whisk cold brew concentrate, milk, condensed milk, vanilla, and salt together for a full minute until completely smooth and uniform.
Taste and adjust — more condensed milk for sweetness, more cold brew for intensity.
Add optional caramel to mold bases if using.
Pour mixture into molds to 1 cm below the top.
Tap molds on the counter to release air bubbles.
Add any mix-ins and distribute with a skewer.
Cover with foil and insert sticks centered in each mold.
Freeze at least 6 hours or overnight until completely solid.
Run warm water over molds for 10–15 seconds to release. Pull gently.
Serve immediately or dip in melted dark chocolate and refreeze for 10 minutes.
Wrap individually in plastic wrap and store in an airtight container.