Brioche dough:
1 1/4 cup (175 grams) of all-purpose flour
3 tbsp (38 grams) of light brown sugar
1 1/4 tsp (4 grams) of instant dry yeast
1/2 + 1/8 tsp (4 grams) of fine sea salt
1 1/2 tbsp (29 grams) of whole milk
2 large (90 grams) eggs
5 1/2 tbsp (79 grams) of unsalted butter, softened
Sour cream and blueberry custard:
1 scant cup (125 grams) of fresh blueberries + 1/2 tbsp of sugar
1/2 cup + 2 tbsp (162 grams) of sour cream or creme fraiche
1/4 cup (70 grams) of sweetened condensed milk
3 large egg yolks
Zest of 3/4 lemon
1/4 tsp of vanilla extract
Finely chopped almonds for sprinkling