All Qt wallets, or just about, have a built in cpu miner for solo mining. You just need to to set gen=1 and genproclimit=<NUMBER OF CORES>, or -1 to use all available cores in the wallet config file. You are better off using an external CPU miner since the wallet miner is usually not optimized for diffrent CPU types and you can only solo mine with the wallet miner.
Can anyone name some (or five or so) Qt wallets?