Choose a substitute category: pick a Best Match for the most similar date-like caramel sweetness.
Start with the listed ratio; if the substitute is lighter (agave, corn syrup), you may need a small boost of vanilla or cinnamon.
If your substitute is thinner than date syrup, simmer it 2–3 minutes to thicken before mixing into batter.
If your substitute is stronger or darker (molasses, honey), reduce slightly and rely on additional liquids/dry balance to keep the batter workable.
Taste-check the batter (for sweetness balance) and bake; expect a slightly different browning rate depending on the syrup.