Perfectly Delicious Pecan Bars

1 1/2 cups quick-cooking or old-fashioned oats
1 1/2 cups all-purpose flour
2 cups dark brown sugar, packed and divided
1 1/2 cups butter, divided (no substitutes)
1 1/2 cups pecan halves
1 cup granulated sugar
1/3 cup heavy cream
2 teaspoons vanilla extract

Heat oven to 350 degrees F.

In a large bowl, combine oats, flour and 1 cup brown sugar. Cut 1/2 cup butter into mixture until coarse and crumbly. Press into 13 x 9-inch baking pan. Place pecans evenly over crumb mixture.

In a heavy saucepan, combine remaining 1 cup brown sugar, granulated sugar and 1 cup butter. Bring to a rolling boil over medium heat, stirring constantly. Boil 3 minutes; remove from heat. Stir in cream and vanilla extract until well blended; pour over pecans. Bake for 35 to 40 minutes. Cool in pan; cut into bars.