Bring a large pot of salted water to a boil over medium-high heat. Add the soba noodles and cook for 6 to 8 minutes, or according to package directions, until they are barely tender. Use tongs to transfer the cooked noodles to an individual-serving bowl, reserving the cooking water in the pot. Return the water to a boil over medium-high heat. Add the edamame and cook until tender, about 5 minutes. Drain and add to the noodles.
Meanwhile, toast the almonds in a small, dry skillet over medium-high heat, shaking the pan frequently, until lightly browned and smelling toasty, 2 to 3 minutes. Be careful not to let them burn. Immediately transfer to a plate to cool. When they have cooled, coarsely chop them.
To make the dressing, combine the almond butter, vinegar, garlic, and red pepper flakes in a small bowl. Add 2 Tbs. hot water, stirring to mix well. If the dressing seems too thick, add more hot water, a teaspoon at a time, until it has reached the consistency you want.
Add salt to taste; add more vinegar if you want the sauce tangier, and more red pepper flakes if you'd like it spicier. Add the dressing to the noodles and edamame, along with the scallion, bell pepper, and chopped almonds. Toss to combine, adding more water if necessary, and eat.
Any leftovers can be refrigerated in an airtight container for up to 3 days.