Fill a large bowl with cold water, add the spelt, and let soak for 10 to 18 hours. Drain. Bring 7 cups of water to a boil in a 4-quart pot over high heat. Add 3/4 tsp. salt. Add the spelt, reduce the heat to a simmer, and cook uncovered, stirring occasionally and adding more boiling water as necessary to keep the spelt covered, until tender, about 45 to 60 minutes. Drain and rinse the spelt with cold water to stop the cooking.
Transfer the spelt to a foil-lined rimmed baking sheet, drizzle with 1 Tbs. of the oil, and toss lightly to coat. Spread the spelt on the baking sheet and cool completely at room temperature or in the refrigerator.
Put the vinegar in a small bowl and gradually whisk in the remaining 1/2 cup of oil. Taste and season with salt, pepper, and additional vinegar or oil as needed.
Put the cooked and cooled spelt in a large serving bowl and toss to break up any clumps. Add the cherry tomatoes, zucchini, scallions, basil, and oregano and 1/2 cup vinaigrette and toss. Taste and season as needed with more vinaigrette, salt, pepper and serve.
The salad can be refrigerated for up to 1 day. If making ahead, let sit at room temperature so it’s not refrigerator-cold and season with more vinaigrette, salt, and pepper before serving.