Preheat oven to 180C.
Place pear pieces into a microwave-proof oven dish, sprinkle with cinnamon and lemon zest and cover. Cook on high for 5 minutes, or until just starting to soften.
Combine flour and brown sugar in a separate bowl and rub the butter in with fingertips until it reaches a ‘crumb’ consistency.
Place the crumb topping over the pear, patting down gently, and bake for 40 minutes or until bubbling.
Serve hot with a scoop of good quality vanilla ice-cream or double cream.