Preheat the oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round cake pans.
In a large bowl, cream together the butter, sugar and dry strawberry gelatin until light and fluffy. Beat in eggs one at a time, mixing well after each. Combine the flour and baking powder; stir into the batter alternately with the milk. Blend in vanilla and strawberry puree. Divide the batter evenly between the prepared pans.
Bake for 25 to 30 minutes in the preheated oven, or until a small knife inserted into the center of the cake comes out clean. Allow cakes to cool in their pans over a wire rack for at least 10 minutes, before tapping out to cool completely.