Preheat oven to 350°F and line an 8″x8″ glass pan with parchment paper. Set aside.
In a standing mixer fitted with paddle attachment, beat the butter and sugars for 1-2 minutes, until light and fluffy. Beat in the egg and vanilla extract for another minute.
In a separate bowl, combine flour, baking soda, salt, and ginger. Stir flour mixture, along with oats, into the wet ingredients.
In a third bowl, mix together blueberries, granulated sugar, lemon juice, and cornstarch.
Place half of the dough into prepared pan, spreading to the edges. Pour in blueberry mixture. Break remaining oatmeal batter into pieces and place over blueberries.
Bake for 30 mins, or until a knife inserted in the center of the bars comes out clean. Allow to cool slightly before serving!