Wash 5 large strawberries and pat dry with paper towel. (You may need more strawberries, depending on how big they are).
In a bowl, combine whipping cream, matcha powder, powdered sugar and vanilla extract and whisk until firm peaks.
Lay out the 2 slices of milk bread onto a work surface.
Spread about ⅓rd of the whipped matcha cream mixture onto each slice of bread.
On one slice of bread with the matcha cream, arrange the strawberries in a diagonal (if you're planning to slice the sandwich diagonally), and then fill in the missing gaps with the remaining strawberries.
Cover the strawberries with the remaining matcha cream, and fill it any gaps.
Place the other slice of bread cream side down to enclose the sandwich.
Make a note of the position the strawberries so that you know which way to cut. (A good way to do this is to take a quick photo on your phone).
Use a large piece of plastic wrap to firmly wrap the sandwich, remembering not to move or rotate the sandwich, and make an indication with ink on the exterior plastic wrap as to the direction you will cut.
Place the sandwich into the fridge to firm up for at least 1-2 hours.
Remove the plastic wrap and while remembering which direction to cut, trim off the edges/crusts with a serrated knife, cleaning the knife in between cuts.
Cut the sandwich in half diagonally (or into quarters).