Got this drill from watching Charles Barkley when he played in the NBA. Even though he was undersized, he could score in the Post. He did two things very well. He used the extra step. He was a master and getting an additional step in. Not a travel, but a step to help improve his angle. Then he was also very good at using the extra dribble. He might use one more dribble again to get a better angle.
The Barkley Move is An effective counter move to power move. Similar to the up and under move. From the Post Position above the block take the ball into the middle of the lane with one or two dribbles.
There are three parts to this move

1. The Lean. The key is to lean into the defender or the middle of the lane.
Drawing the defender in that direction. You want the defender going toward the middle of the lane. Leaning in with the shoulders, not too much to get a charge, but with the shoulders, hips and top foot.

2. The Dribble. The dribble is controlled by the hand closest to the foul line. If leaning in from the right block, lean with right shoulder and dribble with the left hand. Keeping the ball in that hand. (Switch hands if coming from the other block.)
The hand stays on top of the ball and controls the ball.

3. The Pivot. After one or two dribbles make a strong step with the top foot to give balance. Make a pivot maintaining contact with the defense. Pick up the ball with the opposite hand to bring it close to the body. Make a drop step keeping the defender sealed out from a path to the basket. The drop step puts you in position to have a great angle to glass for a jump hook off the glass or power move.

You will see this is a very effective move to Score More Points in the Post by drawing the defender away from the basket and then quickly pivoting to the rim sealing the defender so they can't block the shot. You master this move and you will be the envy of everyone on your team and put fear in the opposition.