For the blintzes: Add all the ingredients to a large bowl and whisk until evenly combined, about 30 strokes. Cover and refrigerate for at least 1 hour and up to 12 hours.
Heat a large nonstick pan over medium heat. Rub the pan with a paper towel dipped in oil. To check that the pan is properly heated, sprinkle the pan with a few drops of water and the water will "dance" around before evaporating.
Add 1/4 cup batter, tilting the pan to evenly cover or spread out in a circle using the back of a spoon. Cook until just set and browned, about 1 to 2 minutes. Flip and cook until second side is lightly browned, about 1 minute more. Remove from the heat and repeat with remaining batter. (Can be made up to 1 month ahead. Stack crepes and store covered in the freezer.)
For the filling: Combine all the ingredients in a large bowl and whisk until smooth. Cover and refrigerate until ready to use. (Can be made up to 1 day ahead.)
For the berries: Combine sugar, water, and 1/2 cup of the berries in a small pan and bring to a simmer over medium heat. Cook until the berries break down, sugar is dissolved, and mixture has slightly thickened, about 5 minutes. Remove from the heat. Add the remaining berries to a small bowl and pour in the syrup. Stir in the lemon juice and let cool to room temperature, at least 30 minutes. (Can be made up to 1 day ahead.) Cover and refrigerate until ready to use.
To assemble: Heat the oven to 375 degrees F and arrange a rack in the middle. Spoon 3 tablespoons of the filling down the center of each crepe. Fold the crepe over the filling, fold in the sides and roll up like a burrito. Put on a baking sheet and repeat until all the crepes have been filled. Bake until warmed through, (the internal temperature should register 160 to 165 degrees F on an instant-read thermometer) and filling is soft, about 15 minutes. Transfer to a serving platter and serve with the berries.