Similar experience in A319 vs B777. 777 at FL350 18 miles in front and routeing in the same direction. We were cleared to FL370. Climbing through FL345 approx we passed through their wake. Aircraft cycled through 3 pitch and roll excursions. 35 degrees bank and plus / minus 10 degrees pitch. All quite suddenly. A/P tripped out unsurprisingly. Even more unsurprisingly nobody was hurt in the cabin.
Filed an ASR, the reply I received was that the company would be very surprised if it was a wake encounter given the spacing. My reply to that was 'not half as f(@&ing surprised as we were'.
Dramatic certainly but had worse CAT over the Pyrenees.