- Heat oven to 350 degrees. Prepare (spray, grease, parchment, butter, etc.) a 9-inch springform pan. 
- Mix up finely ground shortbread crumbs with 2 tablespoons melted butter. Press into the bottom of the springform pan. 
- In a stand mixer fit with paddle attachment, combine cream cheese and sugar until smooth, about 3 minutes on medium-high. With mixer on low, add in milk and then eggs, one at a time. 
- Add in sour cream, flour and vanilla and mix until smooth. 
- Remove bowl from stand mixer. 
- In a food processor, puree blueberries with lemon zest and juice. Pour puree into cream cheese mixture and stir by hand until incorporated. 
- Pour blueberry cheesecake filling onto prepared shortbread crust and bake for 50 minutes to one hour, or until the topping is set. 
- Chill in refrigerator until ready to serve, at least 4 hours. 
- Cover with whipped cream and chocolate sauce.