Grease a 9×13 Pan, set aside. Preheat oven to 350°.
Whisk together the flour, brown sugar and cinnamon in a medium sized bowl.
Cut in the softened butter, with a pastry cutter, until mixture looks crumbly. (This can be accomplished in mixer using wire whisk attachment- but be careful not to overmix)
Remove 1 cup of the crumbs, and set aside. Add in the baking powder, milk and eggs, and mix until just combined.
Stir in apples if using.
Scrape batter into prepared pan, and level out.
Top cake with reserved crumb mixture.
Sprinkle with pecans if desired.
Bake cake for 34-45 minutes, or until it tests done.
Dust cooled cake with powdered sugar or drizzle with icing.
