DOUGH: Add everything except salt and butter to your mixer. Mix till combined then cover and let sit for 15-20 minutes. Uncover and mix. While mixing add in your salt and softened butter. Once gluten has developed (8-10 minutes) remove from mixer and place in a sealed container. Proof for 2 hours with one stretch and fold 60 minutes in. Place in the fridge overnight.
FILLING: Cook down blueberries, honey, and lemon juice with cornstarch till thick and jammy. Let cool completely in fridge overnight.
STREUSEL: Add all ingredients to a mixer and beat until sandy in texture. Refrigerate till butter has completely solidified before using.
ICING: Combine powdered sugar and salt. Whisk 2 tbs blueberry juice into powdered sugar and whisk to combine. If you want more color, add one more tbs juice. Add vanilla then add in 1 tbs of heavy cream at a time till you get your desired consistency. It should stream smoothly off your whisk.
