Preheat the oven to 350F (180C). Butter and dust with flour a 10-inch (25cm) bundt pan.
In a large bowl whisk flour, salt and baking powder. Set aside.
Use a blender to puree the 9 oz (250g) fresh strawberries.
In another bowl mix butter with sugar and vegetable oil until creamy. Add vanilla extract and lemon zest and mix to combine.
Incorporate eggs one at a time. With the mixer on low, alternate adding gradually buttermilk, strawberry puree, and flour mixture until all is well incorporated. At this point add the red food coloring if used. Set aside.
In a medium bowl add the 7 oz (200g) chopped strawberries and add one tablespoon of flour. Toss to coat. Gently incorporate the strawberries into the strawberry batter.
Pour the batter into the prepared pan and smooth the top.
Bake for about 60-70 minutes or until a toothpick inserted into the center comes out clean.
Allow cooling slightly into the pan onto a rack for about 10-15 minutes. Invert and cool completely.