Once you make this granola, you’ll never go back to store-bought.
Heat oven to 325°. Combine oats, walnuts, cinnamon, nutmeg, and salt together in a large bowl. In a separate bowl, mix maple syrup, vanilla extract, and oil. Pour maple syrup mixture over oat mixture and combine until all ingredients are well incorporated. Spread granola onto a large, well-oiled baking sheet and bake 15 minutes. Stir and return to the oven 10 minutes longer. Remove from the oven and allow to cool completely. (Granola can be stored up to 2 weeks in an airtight container.)
Spoon ½ cup yogurt into four glass bowls or 12-ounce brandy snifters. Top each bowl with about ½ cup granola, then an additional ½ cup yogurt. Spoon ⅓ cup Blueberry Sauce over each parfait and garnish with a sprig of mint.
In a medium saucepan over low heat, combine blueberries, lemon zest and juice, and sugar, stirring until blueberries release their juices and the mixture begins to bubble. Add dissolved cornstarch and cook 1 to 2 minutes more, until sauce is slightly thickened. Remove from heat and let cool to room temperature. (Sauce will keep up to 1 week in the refrigerator.)