Date syrup is dates and water, cooked down and strained. Nothing else. It behaves like honey in the pan and like brown sugar on the palate, with a deeper, less floral finish.
The ratio
Use roughly 75ml of syrup for every 100g of sugar, then reduce the other liquid in the recipe by about 20ml. Syrup is already wet, so skipping that second step is why most first attempts come out heavy.
Lower the oven
Drop the temperature by about 10°C. Syrup browns faster than granulated sugar, so a cake that was perfect at 180 will catch at the edges before the centre sets.
Where it works best
Porridge, yoghurt and coffee take it straight. Marinades love it because the sugars caramelise fast against heat. Banana bread, brownies and anything already dark work beautifully. Meringue and light sponges do not: you need dry sugar for structure.
One thing worth knowing
It is still sugar. Date syrup carries minerals that refined sugar does not, and it has a lower glycaemic index, but it is not a health food and we will not sell it as one.