In a small saucepan, whisk together the water and bread flour. Cook over medium heat, whisking constantly, for 4-5 minutes until it forms a paste-like slurry. Scrape it into a bowl and set it aside.

In a stand mixing bowl, mix the flour, sugar, yeast, and salt. Add the cream, milk, egg, vanilla, and tangzhong. Knead on low speed with the dough hook for 2 minutes until it forms a rough dough ball.

With the mixer running on low, add the softened butter one tablespoon at a time, allowing it to fully incorporate before adding more. Continue kneading for another 8-10 minutes or until the dough looks smooth and elastic.

Remove the dough from the bowl and pull the sides into the bottom to form a smooth round ball. Place it seam-side down back into the mixing bowl. Cover with plastic wrap and set aside to rest for 30 minutes.

While the dough rests, make the filling. In a stand mixing bowl, combine the butter, almond meal, sugar, brown sugar, egg, cinnamon, almond extract, and salt until smooth.

Roll the rested dough into a 15×21 rectangle on a lightly floured surface, with the longest side closest to you. Dollop the almond filling across the surface and spread it, leaving a 1/2-inch border clean at the top.

Use a pizza cutter to cut twelve 1 3/4-inch strips. Roll each strip away from you and transfer them to a parchment-lined 9×13 baking pan.

Cover the pan with plastic wrap and set it aside to rise for 1-2 hours or until the rolls double in size. Preheat the oven to 325°F (162°C).

Bake for 30-40 minutes or until the internal temperature of the center rolls reaches 185°F.

While the rolls are cooling, make the frosting by whisking together the powdered sugar, melted butter, heavy cream, milk, and almond extract until smooth. Pour the frosting over the warm rolls and sprinkle with sliced almonds.