Toast 1/4 cup sweet rice flour in a dry skillet over medium heat for 2-3 minutes, stirring constantly, until lightly fragrant. Set aside for dusting.

Make the filling: Melt white chocolate chips with heavy cream in a microwave-safe bowl in 20-second intervals, stirring between each, until smooth. Stir in crushed freeze-dried strawberries, 1/2 teaspoon rose water, and salt until combined.

Pour the filling into a shallow dish and refrigerate for 1-2 hours until firm enough to scoop. Once firm, divide into 8 equal portions and roll each into a ball. Freeze for 30 minutes.

Make the mochi dough: In a microwave-safe bowl, whisk together 1 cup sweet rice flour, sugar, water, 1 tablespoon rose water, and food coloring if using until completely smooth.

Cover the bowl with plastic wrap and microwave on high for 2 minutes. Stir, then microwave for another 1 minute until the dough is translucent and stretchy.

Dust a clean work surface generously with the toasted flour. Turn out the hot mochi dough and dust the top heavily with more flour to prevent sticking.

Once cool enough to handle (about 3 minutes), divide the dough into 8 equal pieces. Work with one piece at a time, keeping the rest covered.

Flatten each piece into a 3-inch circle, dusting as needed. Place a frozen filling ball in the center, gather the edges up and around the filling, and pinch firmly to seal.

Place seam-side down on a parchment-lined tray. Repeat with remaining pieces, dusting off excess flour with a soft brush. Let rest for 10 minutes before serving.