Most of it is a technique thing. You're advancing the throttle too quickly. Here's the deal.

Extra's have tapered wings. Tapered wings stalls begin at the tips. (Wings that have no taper stall from the fuselage out.) When you're starting the takeoff of any airplane, the prop is flying way before the airplane does. The airplane's ability to resist the prop's torque, p-effect, and gyroscopic precession is a function of it's airspeed. It's ability to fight back is lowered the slower it's flying.

Advance the throttle fast and the prop does bad stuff. Do it when the airplane is already cruising along and you don't see anything much happen, because it can't happen. Do it when your airplane is just beginning the takeoff roll and you see something happen because the airframe is barely flying and gets overpowered by the prop. When your airplane has tapered wings, you're almost guaranteed to see something happen. There's less area out at the tips to fight back and hold the airplane level. The rudder is struggling to keep the plane from yawing, and the horizontal tail probably isn't going to help keep the sucker from pitching up or down or both.

When you're flying slowly, work the throttle slowly.

When you're flying a tapered wing model, do it slowly or plan to buy another plane soon. And you'd probably be better off with a wing that doesn't taper too if you can't bring yourself to handle the throttle better.