Soak the Corn Husks: Place the corn husks in hot water in a large pot or kitchen sink, then set a plate over them to keep them completely submerged; soak for at least 1 hour.
Blend the Strawberry Milk: Combine the warm almond milk with 1 cup of the strawberries in a blender and process until completely smooth.
Whip the Butter and Sugar: Beat the room-temperature vegan butter and granulated sugar with an electric mixer on medium-high speed until the butter has doubled in volume and looks light and fluffy, about 3 minutes.
Add the Leavening: Add the baking powder and salt to the whipped butter mixture and beat for 1 minute, ensuring everything is evenly incorporated.
Build the Masa Dough: Add half of the masa harina and mix, then pour in the strawberry-almond milk mixture. Once incorporated, add the remaining masa harina followed by the warm water.
Add the Fresh Strawberries: Add the remaining 1 cup of chopped strawberries and mix on low speed until thoroughly combined. The finished dough should resemble a thick cake batter; if needed, add more water until this consistency is reached. Rest the Dough: For lighter, fluffier tamales, refrigerate the dough for 1 hour. Remove it from the refrigerator and beat it again, adding enough liquid to return it to its previous thick cake-batter consistency.
Prepare the Husks: Remove the soaked corn husks from the water and place them on paper towels. Reserve the largest husks for wrapping and the smaller husks for lining the steamer.
Prepare the Steamer: Add water to the bottom of the steamer, making sure the water level stays below the steamer rack. Line the rack and the sides of the steamer pot with corn husks, then set aside. Make the Tying Strips: Pull 24 pencil-thin strips from the soaked corn husks and reserve them for securing the tamales.
Prepare Each Husk: Take one large corn husk and pat away excess water with a paper towel. Hold it with the tapered end pointing away from you and the smooth side facing upward.
Spread the Masa: Spoon 2–3 tablespoons of dough onto the husk and spread it into a 3–4-inch square about ¼ inch thick, leaving at least a ¾-inch border around each side.
Add the Strawberry Filling: Place 1 tablespoon of strawberry jam in the center of the masa.
Fold the Tamale: Bring the two long sides of the husk together so the masa surrounds the jam, then roll the sides in the same direction around the tamale. If the husk is too small, fold one long side toward the center, then fold the other side over it. Secure the Bottom: Fold the empty tapered portion of the husk upward to create a closed bottom, leaving the top open. Tie the bottom securely with one of the prepared corn-husk strips.
Arrange the Tamales: Stand each tamale vertically in the steamer, leaning it against the side with the open end facing upward. Continue assembling and arranging the tamales until all the dough has been used. Cover the Tamales: Cover the tops of the tamales with a layer of corn husks. If there are empty spaces in the steamer, fill them with additional corn husks.
Steam the Tamales: Cover the steamer and bring the water to a boil. Reduce the heat to medium and steam for 40 minutes.
Check for Doneness: After 40 minutes, check a tamale by seeing whether it separates easily from the corn husk. If the masa still clings to the husk, continue steaming for 10 more minutes and check again. Rest After Steaming: Remove the steamer from the heat and leave it covered for 10 minutes.
Cool Before Serving: Uncover the tamales and allow them to cool for at least 1 hour. They may seem very soft immediately after steaming, but they will firm up as they cool.
