Nesting an encrypted connection inside the traffic being routed through tor is what you would need to protect HTTP traffic from being manipulated and/or monitored by an exit node.

So instead of doing (you -> tor -> internet), do something like (you -> tor -> VPN -> internet). To be even safer do (you -> VPN -> tor ->VPN -> Internet) that way your ISP isn't aware of tor traffic and the exit node cannot manipulate requests.

Easiest way to accomplish that is with a VM. The host has a VPN connection, force route the VM through tor (with something like Tortilla) and install a VPN client on the VM as well. This requires you anonymously set up the VPN running in the VM so there is no connection back to you, of course.