Preheat the oven to 375 degrees F (190 degrees C). Press 1 pie crust into the bottom and sides of a 9-inch pie pan; set aside.

Stir together blueberries, sugar, flour, and cinnamon in a large bowl. Add almond extract; stir to coat. Pour blueberry mixture into the prepared pie crust.

Dot blueberry mixture with butter pieces. Top with second pie crust, crimping the edges together to seal. Brush top crust with milk. Use a knife to cut slits into the top crust for steam to escape while baking. Wrap the edges of the pie with aluminum foil to avoid burning.

Bake in the preheated oven for 25 minutes. Remove foil; continue baking until filling is bubbling and crust is browned, 20 to 25 more minutes. Cool before serving.