Preheat oven to 375°. Grease a 9″x 13″x 2″ baking pan and line with parchment paper.
In a large bowl, combine oats, flour, brown sugar, cinnamon, baking soda, and pecans. Add butter and combine with either a mixer or a pastry blender until crumbs form. Set aside 1 & 1/2 cups of crumb mixture.
Press remaining crumb mixture into bottom of prepared pan. Bake for 18-20 minutes, until golden.
Spread preserves over crust. Drop reserved 1 & 1/2 cups crumb mixture on top of preserves. Bake for 18-20 minutes, until top is golden. Cool completely before removing from pan and cutting into bars.
Make about 24 bars.