With his power. It's called Drawing Life and drawing something, he can bring life to it.

[ Kaworu reaches for the robot, to clean a smudge on its face ] However, Equius is quite capable of doing without his powers. He built robots long before arriving here.

[ The angel moves back to sit on the table, watching the robot moving to the kitchen sink - it's going to wash the baking utensils Kaworu used to make the cake ]

Zadkiel hates it. [ and no one is surprised ]