peel peaches and remove the pit, slice them into wedges, and place them in a medium-sized bowl with blueberries.
Add lemon juice, flour, brown sugar, and cinnamon. lightly stir all together until the fruit is evenly coated in the ingredients, making sure not to crush any of the fruit.
add to the bottom of an 8x9 glass casserole dish.
in a separate bowl add oats, flour, sugar, cinnamon, baking powder, and salt. stir quickly with a fork. cut cold butter into the mixture and pinch together until you have a crumbly dough.
crumble on top of the fruit and place in the oven for 30 min. until the top is golden brown and the fruit is bubbly.