In a medium bowl, combine flour, baking powder, and salt. Set aside.
In a medium mixing bowl, beat butter on high until pale and fluffy. Add sugar and continue mixing until they are thoroughly creamed. Beat in egg.
With mixer on low, add flour mixture and milk to creamed mixture a little at a time, alternating between the two and beating until smooth.
Spoon batter into prepared pan. Evenly distribute berries over top.
Topping
In a small bowl, combine flour and sugar, and then cut in butter with a pastry blender, fork (or your fingers) until the mixture resembles oatmeal. Sprinkle over berries.
Bake in preheat oven 50-60 minutes, or until golden brown. Serve warm, preferably with a scoop of vanilla ice cream.