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 (3 dots in the upper right-hand corner) > "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.