If your levels are dropping the night then you're on far too much Lantus. It's much better to cut your insulin dose than eat to stop you from going low - otherwise you are just feeding the insulin and you'll put on weight extremely quickly. Basal insulins should never lower your blood sugar, they're supposed to keep it constant.
In the meantime, think about exactly what is happening when you're going low in the night. If you eat something like fruit or crackers, all you're really doing is artificially jacking up your blood sugar and giving yourself a cushion, so you're basically trading one problem (hypos) for another (high blood sugar).
A better option might be to eat something that releases glucose slowly, as I'm assuming your hypos happen later than two hours after going to bed. That basically means protein. If nuts are out, then something like jerky/biltong or cheese on its own might be good. Yoghurt is generally a good bet too. Protein shakes can work too but generally feel more like a refuelling exercise.
However, you should really focus on tuning your Lantus dose - you should only need to eat a snack in the evening if you're hungry, rather than to keep your BGs going through the night.
