Preheat oven to 375º Fahrenheit. Grease a 9-inch springform (use the inside of the butter wrapper) and lightly flour the inside. Shake off any excess flour. Set aside.
Crumb Topping
In a medium bowl combine ⅓ cup flour, coconut flakes, brown sugar, and cinnamon. Add ¼ cup butter and mix until moist crumbles form. Set aside.
Batter
Beat one stick of butter (½ cup) and granulated sugar in a large bowl with an electric mixer. Add eggs, one at a time, and beat until well combined. Slowly pour the milk into the batter and continue to beat until smooth.
Sift flour into the batter. Add baking powder and salt. Beat on medium speed until well combined. Use a spatula to fold in the blueberries.
Transfer batter to the prepared springform. Sprinkle crumb topping over the batter.
Bake
Bake cake for 45 minutes at 375º Fahrenheit. Insert a wood toothpick into the center to check for doneness. Cool cake slightly and remove the springform. Serve and enjoy.
Notes
Baking times may vary depending on your location and your oven. Start checking the cake after 40 minutes.