Preheat oven to 325ºF. Spray 9 x 13 in. pan with vegetable pan spray.
In medium bowl, combine flour, baking powder, baking soda and salt. In small bowl, combine nuts, brown sugar and cinnamon.
In large bowl, beat butter and granulated sugar with electric mixer on medium speed until light and fluffy. Add eggs, one at a time, beating well after each addition. Add vanilla. Add flour mixture alternately with sour cream; mix until smooth.
Spread 2/3 of the batter into prepared pan. Sprinkle 1 cup nut mixture over batter and top evenly with apricots; top with remaining batter. Sprinkle with remaining nut mixture. Bake 55-60 minutes or until cake tester inserted in middle comes out clean.