Melt the butter in a small skillet. Add the almonds and cook over moderately high heat, stirring constantly, until golden, about 3 minutes. Drain on paper towels and let cool completely.
In a small bowl, whisk the olive oil with the vinegar and season the vinaigrette with salt and pepper. In a large bowl, toss the spinach with the sour cherries and almonds. Add the vinaigrette and toss well. Add the goat cheese, toss the salad lightly and serve.