Take the cream cheese out of the refrigerator and let it sit at room temperature.
Add milk, strawberry jam, cornstarch, and glutinous rice flour in a mixing bowl. Stir with a whisk until the mixture is smooth. (*See Note 1 if you want to use fresh strawberries or freeze dried strawberry powder instead of strawberry jam. ) Strain the mixture through a fine mesh strainer into a microwave-safe bowl to remove any lumps. Cover the bowl with microwave-safe food wrap, use a toothpick to poke about 12 holes on the food wrap. Microwave the mixture on 100% power for 3 minutes until fully cooked – stick a toothpick into the middle of the mochi dough and if it comes out clean, the dough is fully cooked.
Carefully take the bowl out from the microwave. Remove the food wrap, put a piece of butter on the top of the daifuku dough. Roughly mix the butter and the dough with a nonstick spatula, until all the butter has been absorbed into the dough.
Allow the dough to cool naturally to room temperature on your countertop. Avoid touching the dough with your hands while it's still warm as it will become less sticky as it cools. While waiting for the dough to cool down, you can start preparing the cream filling.
Now the cream cheese we took out at step 1 should have been softened. Add the softened cream cheese and 40g granulated sugar to a mixing bowl, use a hand mixer or a whisk to whip the mixture at medium speed for about 2 minutes until the texture is fluffy.
In another bowl, whip 150g heavy whipping cream and 1 tsp of vanilla extract using medium to high speed of your hand mixer until stiff peaks form.
Transfer the whipped cream into the bowl containing the whipped cream cheese. With a hand mixer on medium-low speed, blend the two mixtures together for approximately 20 seconds until they are thoroughly combined. Optionally, you can transfer the mixture to a piping bag for easier filling of the daifuku later on.
Take 6 fresh strawberries, rinse them and pat them dry. Dice the strawberries into small pieces. You can also mix them with 2 tbsps. of strawberry jam, if desired. Set aside in a small bowl.
Now the daifuku skin dough should have been cooled to room temperature. Knead the dough by pulling and folding it for about 5 minutes, until you can pull it as long as your forearm (about 10 inches).
Cut the dough into 6 equal portions. Wrap a rolling pin with plastic food wrap to prevent sticky.
To make the daifuku into ball shapes, roll each small piece of dough into a 5-inch diameter circle using a rolling pin. Brush glutinous rice flour onto one side of the circle and place the daifuku skin onto a sphere mold with the flour side facing down. Pipe in the cream cheese filling, add some dice strawberries, then cover with more cream cheese filling. Pull the edges of the wrap together to cover the filling, press together the edges to seal well. Flip the strawberry daifuku onto a serving plate so that the smooth side is facing up.
If you don't have a sphere mold, you can make the daifuku in to a pillow shape. Roll each small piece of dough into a 5-inch wide square using a rolling pin. Pipe in the cream cheese filling on the center, add some dice strawberries, then cover with more cream cheese filling.
Fold the sides of the wrap over the filling to form a pillow shape. Flip the strawberry daifuku onto a serving plate so that the smooth side is facing up.
Place a strawberry in the center on top of each daifuku as a decoration.
Serve immediately. Store leftover strawberry daifuku in an air-tight container in the refrigerator for up to 3 days.