Summer's best flavors
Brown the butter: Slice the butter into pieces and place in a light-colored skillet. (Light colored helps you determine when the butter begins browning.) Melt the butter over medium heat, stirring occasionally. Once melted, the butter will begin to foam. Keep stirring occasionally. After 5-8 minutes, the butter will begin browning-- you'll notice lightly browned specks begin to form at the bottom of the pan and it will have a nutty aroma. Once browned, remove from heat immediately and pour into a tupperware or a baking pan. Cover tightly, place in the refrigerator or freezer, and chill until solid. It takes 45 minutes in the freezer.
As the butter chills, whisk the remaining streusel ingredients together in a medium bowl. Set aside.
Preheat oven to 350°F. Lightly grease a 9-10 inch baking dish (circle, square, a skillet, or any similar size pan.
Mix all of the filling ingredients together in a large bowl, then spread into your baking dish.
Scrape butter out of the tupperware or pan and add to the streusel. Use a pastry cutter or a fork to break the butter up into smaller pieces. Combine it with the streusel until the mixture becomes crumbly and all the butter is incorporated. Sprinkle streusel evenly over fruit.
Bake for 40-45 minutes until the topping is golden brown and the fruit juices are bubbling around the edges. Remove from the oven, place on a wire rack, and allow to cool slightly before serving. Serve warm, room temperature, or cold. Cover leftovers and store in the refrigerator for up to 5 days.
Make ahead tip: Baked crisp freezes well for up to 3 months. Thaw overnight in the refrigerator, then warm in a 350°F) for 20 minutes or until heated through. I do not suggest preparing the crisp and storing it, unbaked, in the refrigerator because the topping will get soggy. You can prepare the crisp through step 5 and freeze for up to 3 months. Allow to thaw overnight in the refrigerator, then continue with step 6.