Best Method to Extend Layer 2 and Layer 3 Between Two DCs Over 1 Wave

I'm connecting two DCs with 1 x 10Gbps wave into a Layer 3 switch on each side. Part of this requirement is to:

• Have L3 between both DCs for MPLS / public IP routing
• Have L2 between both DCs for HA failover for firewalls

What is the best method for this? Do I have a routed connection between sites with an EoMPLS / Loopback cable to extend Layer 2 or do I extend Layer 2 directly between sites and use SVIs for routing?

https://imgur.com/BgY0eGL