1 cup firmly packed light brown sugar
1½ cups granulated sugar, divided
4 large eggs
1 T vanilla extract
1 t baking powder
¾ t table salt
3¼ cups all-purpose flour, divided
4 cups fresh blackberries
4 cups thinly sliced fresh firm, ripe peaches
3 T bourbon
1 cup toasted pecan pieces
Preheat oven to 350°.
Beat butter, brown sugar and 1 cup granulated sugar at medium speed with an electric mixer until creamy. Add eggs, one at a time, beating just until blended after each addition. Stir in vanilla.
In a medium-sized bowl, whisk together baking powder, salt, and 3 cups flour; gradually add to butter mixture, beating just until blended. The batter will be very thick.
Spread three-fourths of batter onto a greased and floured 13- x 9-inch pan. Lay blackberries evenly over top of the batter.
Stir together remaining ½ cup granulated sugar and ¼ cup flour in a medium bowl. Add peaches and bourbon, gently blending to coat. Spoon mixture over blackberries.
Stir pecans into remaining batter. Dollop batter over peach mixture.