In a small saucepan, heat the oil, sugar, vinegar, and mustard over medium high heat, whisking constantly until the sugar has dissolved and the dressing emulsifies. Stir in almond extract. Remove from heat and set aside.
For the Couscous
In a medium pan, bring butter and broth to a boil. Stir in couscous, cover, and remove from heat. Allow to set for 5 minutes and then fluff with a fork. Season with salt and pepper. Allow to cool to room temperature.
For the Salad
In a large bowl, combine couscous, spinach, strawberries, feta, and hazelnuts. Stir in dressing and then season with salt and pepper to taste.
Notes
If you are making this salad ahead of time, make all the components, store separately, and assemble just before serving.