Bring a pot of salted water to a boil. Prepare an ice-water bath. Add the edamame and cook until tender, 4 to 5 minutes. Drain the edamame, then shock in the ice water.
Put the edamame into the bowl of a food processor or blender. Add the garlic, scallions, lemon, salt, pepper and chili powder. Add 2 tablespoons of the olive oil. Puree until smooth, 2 to 3 minutes. Taste the mixture and adjust seasoning if needed. Add more olive oil to get a smoother consistency.
Transfer dip to a bowl and serve with sliced pita bread, chips and/or veggies.
Store in an airtight container in the refrigerator for up to one week.