Slow down first layer above infill in Ultimaker Cura
Cura can do this. It's a bit convoluted though. Here's what you need to do:


Load your model / scene in the build plate.
Load an additional cube and make it as big as the entire build plate so that it overlaps with everything (in the preferences you may need to disable "Ensure that models are kept apart).
Select the cube and go to the per-object settings tool.
Change the cube's mesh type to "modify settings for infill".
For the cube, set Wall Line Count to 0, Top/Bottom Thickness to 0 and Top Layers to 1. This effectively makes the cube add one additional layer on the top side of all infill volumes.
For the cube, set the Top/Bottom Speed to your desired speed for the one slower layer.
(Optional) In the normal settings panel on the right, set the number of top layers to be one less, so that you get the same number of top layers again.