Prepare the Blueberry Pie Filling by combining blueberries, granulated sugar, cornstarch, and lemon juice in a saucepan over medium-high heat. Stir frequently for about 10 minutes until thickened. Let cool.
Mix the Bread Batter by whisking together melted butter and granulated sugar, then adding eggs and milk one at a time. Fold in flour, baking powder, salt, and vanilla extract until just combined. Fold in cooled blueberry filling.
Prepare your loaf pan by greasing it and preheating the oven to 350°F (175°C). Pour the batter into the pan and smooth the top.
Make the Almond Crumble by mixing melted butter, flour, sugar, and almond paste until clumps form. Sprinkle over the batter in the loaf pan.
Bake the bread for about 50-60 minutes until a toothpick comes out with a few moist crumbs. Cool in the pan for 10 minutes before transferring to a wire rack.