1Heat oven to 350°F. Grease and flour 13x9-inch pan. In large bowl, beat all cake ingredients on low speed 30 seconds, scraping side and bottom of bowl frequently. Beat on medium speed 4 minutes. Pour into pan.
2Bake 35 to 40 minutes or until toothpick inserted in center comes out clean.
3In large bowl, mix sour cream and brown sugar until well blended. Gently stir in strawberries. Spread topping over warm cake. Store in refrigerator.