This is maceration not fermentation but I unintentionally did something similar with red currants and wine. I don’t know how I made it but it was partly fermented with sugar wine and vodka (or some other clear distillate) to add more alcohol to be stable.

Found bottle few weeks ago and it was amazing, I forgot about it after I tasted it and don’t liked it few years ago.

I don’t like distillates that much, bit too strong for me, but basically fruit+bit of sugar+time+still and you have some eastern Europe pálenka/slivovice (from plums) or other “moonshine”.