Add the milk, water, eggs, flour, sugar, and salt to the bowl of an electric stand mixer with the whisk attachment.
Whisk on medium until the batter is smooth, and there are no lumps/flour pockets, about 30-60 seconds.
Scrape down the sides of the bowl. With the mixer on the lowest setting, slowly add the melted butter in a steady stream, and continue to mix until just incorporated.
Transfer batter to a medium bowl, cover with plastic wrap, and chill for one hour (or overnight) before using.
MAKE FILLING:
In the clean bowl of an electric stand mixer with the paddle attachment, add the cream cheese and ricotta and beat until on medium until smooth, about 30-60 seconds.
Add the powdered sugar and egg and mix on medium until combined and not lumpy, about 30-60 seconds.
Transfer mixture to a bowl, cover with plastic wrap and chill for 1 hour (or overnight) before using.
MAKE CREPES:
Preheat an 8-inch skillet over medium heat and brush with a little melted butter.
Add a scant ¼ cup of the crepe batter to the pan, swirl around to cover the bottom of the pan evenly, and pour any excess back into the bowl.
Cook for 30-45 seconds or until the crepe batter sets.
Gently loosen the crepe, flip it with a rubber spatula, and cook for 30 more seconds. The crepe should not be crisp but flexible and light brown.
Transfer the crepe to a plate and cover it with a towel until ready to make into Blintzes. Repeat with the remaining crepe batter.
ASSEMBLE BLINTZES:
Preheat oven to 400°F and move the oven rack to the middle position.
Place a crepe on a clean surface and add ¼ cup of the filling to the lower third of the crepe.
Fold like you would a burrito (see pictures above) by folding up the bottom edge of the crepe on top of the filling; then fold in the two sides. Roll the crepe to make a little burrito with the seam facing down.
Set aside and assemble the remaining Blintzes.
Brush the blintzes with butter and add them to an oven-safe skillet over medium heat.
Cook the Blintzes in the skillet for two minutes per side or until golden and crisp (you may need to do this in batches, depending on your skillet's size).
BAKE:
Pop the pan into the preheated oven and bake for 10 minutes, giving the filling time to cook and set up.
TO FINISH:
Transfer the Blintzes to a plate, top with chopped strawberries and a dusting of powdered sugar. Serve immediately.