In a large mixing bowl, beat the butter, oil, and sugars until combined.
Beat in eggs, vanilla, lemon extract, and lemon zest.
In a large bowl, whisk together flour, baking soda, and cream of tartar.
In two additions, add flour mixture to the butter mixture, beating until just combined. Do not overmix. Dough will be kinda fluffy and light!
Gently and carefully fold in freeze-dried blueberries. They're a bit delicate.
Line baking sheets with parchment paper or silicone baking mats.
Drop dough by rounded teaspoonfuls onto baking sheets.
Bake at 375 for 8-11 minutes, or until edges and bottoms are lightly browned.
Remove to wire racks to cool.
Meanwhile, prepare lemon glaze.