I need to setup a NIC team, using LACP on a Dell Server.
I have two switches, up-linked together (not stacked).
Is it possible to create a LACP group, two ports, one port from each switch?
Unfortunately, no. There needs to be single device controlling all links for LACP to work correctly, so stacking is a minimum requirement for your switches to do this.
If you're looking for failover functionality in the event of a switch failure, there are other options depending on what you're running on that server. You can bridge the two links and rely on the switches' spanning-tree protocol to block one of them, for example.