Peel and chop the apples, place them in a microwave safe dish and pre-cook them in the microwave for a minute on high with a little water, lemon juice and a teaspoon of brown sugar. As it is cooking, mix together the butter, flour, brown sugar, cinnamon and oats in a small bowl. Use a pastry blender or fork to make the mixture turn into coarse crumbles.
Remove the apples from the microwave and pour the crisp mixture on top. Microwave on high 2-3 minutes longer until the top is bubbly and brown. Serve with whipped cream if desired. Enjoy!