In a medium saucepan over medium heat, combine cherries, sugar, and cornstarch. Cook while stirring for about 5-7 minutes until thick and bubbly. Remove from heat, stir in lemon juice and almond extract, and let cool.

Preheat oven to 400°F (200°C) and line muffin pan with paper liners. In a large bowl, whisk flour, baking powder, baking soda, and salt. Cut in butter until mixture resembles coarse crumbs. Add buttermilk and egg, mixing gently.

Prepare crumble topping by mixing flour, brown sugar, and cinnamon. Cut in cold butter until crumbly.

Spoon muffin batter into liners, filling halfway. Add a tablespoon of cherry filling to each muffin and sprinkle crumble topping evenly.

Bake for 18-22 minutes or until a toothpick comes out clean. Let cool in the pan for a few minutes before transferring to a wire rack.