I watched this on tv sometime in the nineties. It was in English and in color. I was very young so I only remember two scenes:

– montage of the two sisters growing up. They’re always in competition. They each bake a cake and when the good sister’s cake comes out perfectly, the evil sister casts magic to make it flop.

– the good sister is grown up and walking through the desert. She encounters an African woman with a water flask who offers her a single drop of water. She lets it fall onto her tongue.

It’s one of those movies with knights and kings and women in long dresses. Maybe with a dragon somewhere even? It definitely featured magic. Please help it’s driving me crazy!