Soufflé pancakes can deflate if the egg whites are under-beaten, overbeaten, or if you didn't cook the souffle long enough. The perfect soufflé - whether baked in the oven or in molds as Japanese pancakes - relies on just the right protein structure in the beaten whites. A soft-to-medium peak meringue is ideal for soufflés of any kind. And be sure to cook the pancakes after flipping until the tops spring back when gently pressed. It can take up to 15 minutes of cooking on low heat to set the egg whites in a soufflé pancake.