Hi, Vany, I use a simple syrup, which can be easily flavored – I love to steep a stick of cinnamon in the simple syrup for 5-10 minutes – it makes the syrup taste really nice.
I’ve also added Amaretto, rum, coconut emulsion, or anything else you like. I brush the simple syrup on my cakes (all layers) especially around the edges where it tends to dry out. The result is a very moist cake every time. Hope this helps!