How to "Multi-Task" on a Piano?

i have the same problem all the time. What helps me is to practice each hand separately (at the same speed), then put them together and play it extra s l o w l y to see where the notes in each part should be falling in relation to each other. It also helps to briefly disregard the dynamics and to really pound out each key so you can feel when the notes should be hitting. I hope this helps, good luck!