The one I got was Llloyds bank - 0.25% cashback on every £1 you spend up to £4,000, and 0.5% for every £1 you spend over £4,000 intro offer was £20 if you spend £1000 in first 90 days which I have already. Payout is each January.
There may be better but I didn't trawl around much. They gave more credit than I asked for but like you it's on full outstanding DD.