Preheat oven to 350 degrees

Line a 8x8 square baker with parchment paper and set aside.

In a medium size bowl cream sugars and softened butter with a hand mixer.

Add vanilla extract, lemon juice, lemon zest and eggs. Mix well and set aside.

In a small bowl add cinnamon, salt, baking powder and flour together. Mix into wet ingredients.

Cut blackberries in half and gently fold into batter. Be careful not to overmix.

Add white baking chips and gently fold in.

Spread the batter into the bottom of the prepared pan.

Bake at 350 degrees for about 25 minutes or until a toothpick inserted in the center comes out clean.

Remove from the oven and cool on a wire rack.

While the bars are cooling, mix up the icing in a small bowl. Add just enough lemon juice until the consistency is what you like

Cut bars into squares and remove from pan.

Drizzle icing over bars and garnish with additional blackberries and lemon wedges, if desired.