Preheat oven to 400o F. Toss eggplant with salt in colander; allow to drain in sink 30-45 minutes. Pat with dry paper towels to remove excess salt and moisture. Coat an 11”x16” baking sheet with Pam®. Spread eggplant in a single layer and spray with additional Pam®. Sprinkle evenly with pepper, garlic powder, and Italian seasoning. Bake at 400o for 25 minutes or until just done.
While eggplant cooks, toast walnuts in dry pan on stove over medium heat until just golden. Cool to room temperature. Combine spinach, basil, chopped garlic, ¼ teaspoons salt, and walnuts in a small chopper or blender. Pulse at low speed until greens are chopped. While processor is running, stream in olive oil. Continue to pulse until mixture forms spreadable sauce. Refrigerate until eggplant is finished cooking.
After eggplant is done, increase oven temperature to 425o. Prepare pizza crust mix as directed. Coat a 10”x14” baking sheet with Pam® Cooking Spray. Spread dough to edges of sheet, forming a rough rectangle. Bake at 425o for 5 minutes. Remove crust from oven. Spread pesto over top of crust to 1” from edge (there will be some pesto left over). Scatter onions, peppers, and roasted eggplant over pesto (depending on the size of the eggplant, there may be some left over). Top with ¾ cup Mozzarella cheese. Return to oven and bake for and additional 12-15 minutes, until cheese just melts and crust is brown on bottom. Remove from oven. Scatter shrimp over top of pizza. Top with remaining Mozzarella cheese. Continue baking for 3 minutes or until cheese is melted and shrimp are heated through.