If it's flaky rather than crusty it could be the normal skin 'peeling' away as new skin grows. Normally they will get rid of it through their normal grooming routine, so it could be a sign maybe that Bramble is a little off balance, stiff or wobbly and unable to clean inside them properly. Skin issues inside ears can also be a sign of ear mites. Dudley gets flaky skin in his ears sometimes as his balance isn't that great these days so he sometimes struggles to bend round to clean them properly.
Has Bramble seemed at all wobbly or stiff recently?