How do they get the filling into donut?

There are a few different ways that donuts are filled. One common method is to use a filling injector, which is a device that injects the filling into the donut hole. Another method is to use a pump, which sucks up the filling and then pumps it into the donut. Finally, some donut makers simply use a spoon to spoon the filling into the donuts.

No matter which method is used, the key is to ensure that the filling is evenly distributed throughout the donut. This can be done by rotating the donut while injecting or pumping the filling. Once the donut is filled, it is then fried or baked until it is cooked through.