Rinse the apple. Cut the apple in half and scoop out the center seed/core of the apple and the end stem pieces. Place the two apple pieces onto a microwave safe bowl or plate. For the crumble, combine all of the ingredients into a food processor and pulse until the ingredients are well combined and chopped. Sprinkle one tablespoon of crumble onto the top of each apple. Microwave the apple for 3 minutes. Remove from the microwave and sprinkle with extra crumble if you like. Serve warm. Also great with vanilla ice cream on top :)