Preheat oven to 350˚ F. Using a baking spray, generously grease the cake pan. I use a Bundt pan 12-cup capacity.
In a large bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
In another bowl, stir together strawberry puree, oil, buttermilk, and vanilla extract. Set aside.
In a large bowl, beat butter and sugar until creamy with an electric mixer on medium-high speed. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed.
Reduce speed to low and add half of the flour mixture. Scrape down the mixing bowl with a spatula and turn the batter over several times to ensure all of the ingredients are well incorporated. Add the buttermilk mixture; continue beating to incorporate. Add the remaining flour; beat just until combined. The batter is thick. Do not over-mix and a few lumps are okay. Over-mixing will lead to a tough, dense textured crumb.
Pour the cake mixture into the prepared pan. Bake for 40 – 50 minutes (for a bundt pan, if you are using another type of pan see note for baking times), or until a skewer comes out clean when poked in the center. NOTE: Baking times vary, so keep an eye on yours. The cake is done when a toothpick inserted in the center comes out clean.
Once done, remove from the oven and allow to cool for 10 minutes inside the pan. Then, invert the cake onto a wire rack or serving dish. Allow cooling completely before icing and serving.