In the bowl of a food processor or blender, puree the shrimp.
In a large mixing bowl add the shrimp, crabmeat, fish sauce, lime juice, scallions, cilantro, Thai chilies, ginger, salt, egg and ¼ cup of the breadcrumbs.
Gently mix with your hands until the mixture is fully incorporated but the crabmeat is still in large pieces.
Form the mixture into ¼ cup balls and flatten them out. Add the remaining breadcrumbs to a shallow bowl and coat the crab cakes in the breadcrumbs on both sides.
Heat a large sauté pan over medium heat, add the peanut oil and heat through. Working in batches, add the crab cakes to the pan and sauté until golden brown on both sides, about 6 minutes total.
Remove crab cakes from a pan to a paper-towel lined plate to drain any excess oil and repeat with the remaining crab cakes.