A downhill slope in a bunker is not fun, as the ball comes out low and runs out. So landing next to the pin is not to be expected. The goal with a downslope in the bunker is to get out and on with your life.
Angle your shoulders with the slope. This is key to avoid skulling the ball. Position the ball back of center. Your weight should favor your front leg to complement your shoulder angle.
Swing down the slope and keep your weight moving forward. The ball will have minimal spin, if any, and will come out of the bunker low.