Whisk 1 ¾ cup flour, 1 teaspoon baking powder, ½ teaspoon baking soda, 1 teaspoon dried ginger, and ½ teaspoon salt in a bowl. Using a handheld mixer with beaters, or a stand mixer with paddle attachment, cream ¾ cup butter 1 cup sugar together on medium-high speed until light and fluffy, about 3 to 5 minutes. Add 2 eggs, one at a time, scraping down sides of bowl after each addition.
Stir in the flour mixture in three additions, alternating with buttermilk in two additions, beginning and ending with dry ingredients, and scraping down the sides of the bowl occasionally. Gently fold in 1 pound fruit.
Spread the batter into the prepared pan, then sprinkle the crumb topping over the cake.
Bake for 45 to 50 minutes, or until lightly golden, and firm on top. If using springform pan, cool on wire rack 5 minutes, then unlatch springform.
Cool completely before serving.
Store wrapped in plastic, at room temperature, for 2 to 3 days.