Coat the apples in lemon juice and sugar and evenly spread out to the bottom of a small cast iron skillet.
In a medium bowl cut together the butter, flour, brown sugar, oats and pecans using a pastry knife until the butter is the size of rice.
Top off the apples with the oat mixture until completely covered and bake in the oven at 350° for 35 to 40 minutes or until the top is browned and crispy.