@Hovis I'm not sure a ready made filler will cure that well on the deeper chunks. You might want to get a small sheet of plaster board and use some adhesive to stick it on (called dry wall adhesive) then get a ready made skim mix to go over the top. It'll certainly dry quicker.
You can get some deep fillers but its looks like quite a large area to fill.
@Hovis I'm not sure a ready made filler will cure that well on the deeper chunks. You might want to get a small sheet of plaster board and use some adhesive to stick it on (called dry wall adhesive) then get a ready made skim mix to go over the top. It'll certainly dry quicker.
You can get some deep fillers but its looks like quite a large area to fill.