Preheat oven to 325°. Brush an 8-by-8-inch baking dish with oil. Line bottom and two sides with parchment paper, leaving a 2-inch overhang on each side. Brush paper with oil. In a bowl, combine spelt, cherries, flaxseeds, pecans, pistachios, and salt; set aside. In a small saucepan, combine honey, peanut butter, oil, and vanilla. Cook over medium until melted. Add to dry ingredients and stir to combine. Transfer mixture to prepared pan; smooth top. Bake until golden and edges pull away from sides of pan, 20 to 25 minutes. Cool completely in pan. Using paper overhang, lift bars out of pan. On a cutting board, cut into 8 pieces using a serrated knife. Store in an airtight container, separating pieces with wax or parchment paper, for one week.