• Move oven rack to middle position. Preheat oven to 375℉.
• Line 8-inch square baking pan with parchment, leaving a generous overhang on all sides. Add a second piece of parchment to overhang on the opposing two sides.

Bottom Layer (Crumb Mixture)

• In stand mixer combine flour, sugar and xanthan gum. Mix for 30 seconds.
• Add butter pieces and beat until mixture is a uniform crumb that holds together when squeezed in your hand. It will look dry.
• Set side ½ cup of crumb mixture in medium bowl, to make the streusel topping.
• Press remainder of mixture into prepared baking pan pushing it to an even thickness being sure it goes right to the edges.
• Bake in preheated oven 10-12 minutes until beginning to brown around the edges.

Prepare Fruit Filling while crust is baking

• In a small bowl combine jam, berries and lemon juice. Using a fork, gently mash the berries leaving some pieces visible. Set aside until ready to use.

Prepare Crumb Topping while crust is baking

• In bowl with reserved crumb mixture add brown sugar, pecans and oats. Use your hands to mix to uniform consistency. Pinch mixture with fingers to make small clumps. Set aside.

Final Assembly

• Spread fruit filling over base. Sprinkle streusel topping over whole pan. DO NOT press the streusel into the filling.
• Return to oven and bake another 22-25 minutes. Turn pan half way through baking time, especially if you know your oven cooks unevenly.
• Transfer to wire rack to cool completely before cutting, about 1 hour. Cut in 5 on each side for 25 squares or cut bars to your liking.