Preheat oven to 375°F. For easy removal of bars from pan, cut two strips of foil to line a 13 x 9-inch pan, one lengthwise and one width-wise to overhang the edges.
Spray the foil with cooking spray; or, use a non-stick pan and spray with cooking spray only.
Mix flour, sugar, ½ of the scraped Rodelle Vanilla Bean seeds, and salt with a paddle attachment at low speed until combined. Add 16 tbsp of butter, one piece at a time and continue mixing on low speed until the mixture resembles damp sand.
Measure out 1 ¼ cups of flour mix into a medium bowl and set aside.
Distribute remaining flour mixture evenly into the bottom of the baking pan. Press the mixture down to make a bottom crust. Bake until the edges are brown, about 15 minutes.
To make streusel topping, combine the brown sugar, the remaining scraped Rodelle Vanilla Bean seeds, and oats into the reserved flour mixture. Work the 2 additional tbsp of butter into the mix by rubbing the mixture between your fingers until the butter is fully incorporated and you have ¼ inch size clumps.
In a small bowl, combine the raspberries and lemon juice. Smash with a fork leaving some raspberry chunks.
Spread the raspberries over the cooked crust. Sprinkle streusel topping evenly over raspberries. Bake until the topping is golden brown and filling is bubbling, about 20 – 25 minutes. Cool on wire rack. Remove by lifting the edges of the foil.
