Cannonau Di Sardegna is from Sardinia. Cannonau is the Italian name for the Grenache grape, used in rose from France and super popular in Spain as garnacha. If you're looking to make a wine that tastes like cannonau, it would be best to start with Grenache... You can likely get grapes from Spain to do so through some good distributors. I would also recommend doing much much more research and reading, back sweetening red wine from grapes is not a technique I would recommend unless you are seeking a dessert wine.... It's possible you tried a version if cannonau called licoroso (I think that's the name) that is a fortified version if the wine, has added alcohol and sugar and is sort of like a port in that sense.... It's sweeter and usually around 20% ABV...
But I would concentrate on research, yeast selection, brix, ph, acidity, skin contact and maceration, nutrients, temperature, racking and aging... You sort of need to understand these to really control the outcome for your wine, unless you are working with kits.
Yeast selection alone can have a great deal of influence on the outcome.
I suspect you are not seeking sweetness but a fruit forward character. Most red wines are dry, but they are not always tannic or oaky, they can be much more fresh tasting and perhaps that is what you are seeking.
A similar light red wine grape to Grenache is Gamay... The grape used in Beaujolais nouveau... I would pick up a bottle of that for a under $10 to try and see if that is the sort of taste you're seeking.