Into a small saucepan, add the brown sugar, cinnamon, salt, and water. Heat over medium until bubbling. Cook, stirring occasionally, for 1 minute.
Add the walnuts and toss to coat. Cook for another 1 to 2 minutes or until the walnuts are fully coated and the sauce has become thick and sticky.
Transfer the walnuts to the prepared baking sheet. Cool at room temp for 1 hour or in the fridge for 10 minutes. Break apart any large pieces.
Balsamic Vinaigrette
In a bowl, whisk together the balsamic vinegar, brown sugar, mustard, salt, and pepper.
Then, very slowly, drizzle in the olive oil whisking the whole time. (see note)
Assemble the salads
For individual salads, divide the spinach between 4 bowls. Top each with an equal amount of strawberries, red onion, goat cheese, and candied walnuts. Drizzle the salads with the dressing or serve it on the side. Serve immediately.
For a large family-style salad, place the spinach in a large bowl and toss with just enough dressing to coat the leaves. (Note, you'll probably have extra dressing to serve on the side.) Then, top with the strawberries, red onion, goat cheese, and candied walnuts. Serve immediately.
Notes
Notes:
When adding the olive oil to the dressing, you want to pour it VERY slowly. Practically a drizzle. If you pour a bit too fast, stop adding oil and whisk vigorously until everything comes together. Then, continue adding the oil slowly.
The dressing can be made in a food processor. Simply everything except for the oil to the food processor and pulse to combine. Then, slowly pour the oil in through the feed tube on top while the processor is running. This will result in a thicker dressing but is easier than mixing by hand.
Storage:
Store the components separately in airtight containers in the fridge. Assemble just before serving.