Remove the skin and pith from one of the oranges and separate the segments. Put them in a bowl and set aside. Using the second orange, zest it until you get 1/2 of zest. Juice that orange and try to get at least 1 1/2 Tablespoons of juice out of it. In a small bowl, whisk together the zest, juice, minced shallot, Dijon mustard, and salt. cover and let the dressing stand on the counter for 15 minutes.

In a small skillet over medium heat, toss the chopped nuts (if using) until they are heated through and fragrant. This will take between 4-5 minutes and make sure they don't burn.

Going back to the dressing, whisk the dressing and then slowly stream in the olive oil until it is emulsified--fully combined and thick and smooth. Pour the dressing into a large bowl and stir in the avocado, raspberries, spinach, and orange segments. Toss gently and divide the salad onto 4 plates. Top each salad with the toasted nuts.