Rinse the sushi rice under cold water until it runs clear.

Combine rice and water in a pot, bring to a boil, then reduce heat, cover, and cook for 15 minutes.

Remove from heat and let sit covered for 10 minutes.

Stir in sugar, vanilla extract, and milk while the rice is still hot. Let cool completely before assembling.

In a chilled bowl, beat heavy cream to soft peaks.

Add vanilla and powdered sugar, then beat to stiff peaks. Don't overmix.

Lay plastic wrap over a bamboo sushi mat and spread cooled rice into an even rectangle, about 1/2 inch thick, leaving a small border at the top edge.

Spread whipped cream down the center and line up whole strawberries on top.

Roll tightly using the mat, sealing the edge gently.

Wrap tightly in plastic wrap and refrigerate for 20-30 minutes to firm up.

Unwrap and slice into 1-inch pieces using a sharp knife dipped in warm water, wiping the blade between cuts.

Garnish with sliced strawberries, a drizzle of strawberry syrup, melted chocolate if using, and a dusting of powdered sugar. Serve immediately.