Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large bowl, beat the sugar, butter, and dry strawberry gelatin together with an electric mixer until light and fluffy.
Add eggs one at a time, beating well after each addition.
In another bowl, combine the flour and baking powder. Gradually stir this into the butter mixture, alternating with the milk.
Blend in the strawberry puree and vanilla extract.
Divide the batter evenly between the prepared pans.
Bake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean.
Let the cakes cool on a wire rack for 10 minutes, then run a table knife around the edges to loosen. Invert onto a serving plate or cooling rack to cool completely.
