Make the Dressing: In a small bowl or jar, combine 1/4 cup olive oil, 2 tablespoons apple cider vinegar, 1 tablespoon honey, 1 teaspoon Dijon mustard, 1/2 teaspoon poppy seeds, 1/4 teaspoon salt, and 1/8 teaspoon black pepper. Whisk or shake until creamy, then set aside.
Prepare the Salad: In a large bowl, gently toss 5 ounces fresh baby spinach with 1 cup sliced fresh strawberries, 1/2 cup fresh blueberries, and 1/2 cup fresh raspberries.
Add Toppings: Evenly sprinkle 1/4 cup crumbled goat cheese and 1/4 cup chopped pecans over the salad.
Dress and Serve: Just before serving, pour the poppy seed dressing over the salad and toss gently to coat. Serve immediately.