If you no longer want to use a specific bank account in Cake you can easily delete that account.
Go to the settings in Cake (Tap the Cake icon at the top right of the screen and then at the bottom on Control centre) > "Bank accounts" > click on the bank account you want to delete > “Delete this account”.
This means you will no longer earn Rewards with that account.😞
You can also choose to disconnect an account. That means transactions won't be synced anymore, but you will still see the historical data in Cake.