What is recommended spacing between controls for a fat finger friendly interface?

I have tried searching anything related to fat finger friendly sized controls and spacing between. I could only find that it is a common rule to make controls at least 44 pixels big (from what I understood, that would be both in height and width).

I was unable to find anything related about the space between those controls. Would anyone have any more information regarding what the recommended amount of pixels between controls (e.g. buttons) would be for a fat finger friendly interface?