Cook ground beef in a large skillet over medium heat until meat is browned and crumbly, about 10 minutes. Season meat with cumin, chipotle pepper, ancho chili powder, and salt. Stir in poblano pepper slices and green onions; cook until beef juices caramelize onto beef and peppers.
Hold a paper towel with tongs and use it to wipe the skillet clean of excess grease. Tilt the pan to get as much as possible.
Pour marinara sauce into meat mixture and continue to cook and stir until pepper strips are slightly tender, 2 to 3 more minutes.
Roll pizza crust into a large rectangle on a floured work surface and place onto a large baking sheet lightly dusted with flour. Use tongs to pick out pepper strips from sauce and distribute them evenly onto the crust; spread rest of meat sauce over crust.
Spread pepperjack cheese over top.
Place pizza on the bottom of the preheated oven and bake for 6 minutes. Move pizza to the middle of the stove; continue baking until pizza crust is browned and cheese is bubbling and melted, 8 to 10 more minutes.
Remove pizza from pan and slide pizza onto a cooling rack to prevent crust from becoming soggy. Cool for about 10 minutes before slicing.
