The pilot reported that he was practicing takeoffs and landings at his home airport. As he made a left turn over a hangar, a crosswind increased, and the airplane banked too steeply. The left wing subsequently stalled and the airplane was too low for the pilot to recover. The airplane impacted the ground near a hangar. A witness stated that shortly after takeoff, the airplane returned and made a low pass at the airport. He observed the airplane then fly low over the pilot's restaurant and subsequently stall/spin at low altitude. During the stall, the witness heard the engine noise increase to full power. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. The recorded weather at the accident airport, about the time of the accident, included clear skies and calm wind.