How to mosaic to give the the mean value of overlapping pixels?

I would like to mosaic multiple overlapping scenes to get a mean pixel value for 1 band. I thought i might use the mosaicing tool for this, but I don’t see an option to control which pixel value is preserved in the mosaiced image.
Does anyone have suggestions?

For mosaicking the arithmetic mean of all valid pixels is used. If you would like to have more control over the aggregation process you should think about using the L3 Binning. There you can select different aggregation methods.