Heat oven to 350°. Butter and flour a 10-inch tube pan with a removable bottom.
Topping In a small bowl, combine flour, sugars and cinnamon. Cut in butter until crumbly.
Batter. In a medium bowl, whisk together flour, baking powder and salt.
In a large bowl, beat butter until smooth. Add sugar; beat until fluffy. Beat in egg and vanilla. On low speed, add flour mixture alternately with milk, beating well after each addition.
Spread half the batter in prepared pan. Cover with blueberries and cherries. Drop remaining batter on top by tablespoonfuls. Cover with topping.
Bake at 350° for 50 to 55 minutes, until golden brown. Remove pan to a wire rack. Run a small offset spatula around side. Cool for 15 minutes. Remove side. Run spatula around center and bottom of pan; place 2 wide spatulas under cake and gently lift cake from pan bottom. Serve with crème fraîche, if desired.
