This has got to be from a good 30 years ago. In color, live-action. I watched it in English.
Some kids (two boys, I think) started making milk shakes from cake batter and selling them at a restaurant. (Or maybe they were just cups full of raw cake batter.) Then the company that made the mix they were using to make the cake batter sued or threatened to sue the kids, so they stopped. I don’t remember any courtroom scenes, so maybe the kids just got a letter or a visit from the company’s lawyer.
I’ve tried searching, but all I get are recipes!