I typed in Rumboph and got a website GermanDeli.com with a receipe listed if this helps.

I have made this several times.It's been a few years but I remember you just peel and slice the fruit and put it in a crock with a tight fitting lid.I used a 1 gallon glass jar.Peel and slice about a pound of fresh fruit and add about 1 cup of sugar.Pour enough rum over the fruit to cover it about 1 in. over the top.Cover the container with saran wrap then the lid.Once a month add another layer of fruit and add more rum to cover the fruit.You can add all the fruit,sugar and rum at one time but it takes several months to develop the flavors.
You can use fresh pineapple cut into large cubes,cherries(I think I used jarred maraschino cherries),nectarines,
peaches,pears and seedless grapes.
Watermelon,apples,cantaloupe,bananas and citrus fruits don't work well.
Store in a cool place away from heat and direct sunlight.You can also store it in the refrigerator.
I served it over pound cake and sometimes vanilla ice cream.I think you can also drink the juice as an after dinner cordial but we never did.I remember it was really good! I may just try it again.LOL Thanks for reminding me Jasdip.

That sounds like what we call brandied fruit.

I have an authentic Rumtopt container but haven't used it in years.
But I can't remember how to make it....seems like it came with fruit and rum in it and all I did was add more fruit off and on.
It was good.

traditionally the first fruit of the season is in there first. Not sure about the amounts of sugar, but fruit, sugar, and the over with rum.

Next fruit of the season repeat as above, repeat with all fruits throughout the year. By the end of the year you have powerful fruit, to spoon over sponge cake, or ice cream, or just nip at.

I am not at home, and have no recipe handy. Try to remember to post it later.

Moni