Crush graham crackers into fine crumbs. Mix with sugar, then stir in melted butter until well combined.
Press mixture firmly into bottom of 9x13 baking dish. Freeze for 20 minutes.
Whisk lemon pudding mix and half and half for 1 minute. Let sit for 5 minutes to thicken.
In another bowl, beat cream cheese and powdered sugar until smooth and creamy.
Add thickened pudding to cream cheese mixture and blend until combined.
Gently fold in one container of Cool Whip.
Spread lemon mixture evenly over chilled crust.
Spoon blueberry pie filling over lemon layer and spread evenly.
Top with second container of Cool Whip, spreading to cover.
Cover and refrigerate at least 8 hours or overnight.
Optional: Garnish with fresh blueberries or lemon slices before serving.