Preheat the oven to 350F degrees. Grease and flour a 9x5 inch (23x13 cm) loaf pan. Alternatively, line the bottom with baking paper and grease and flour the sides.
In a large bowl, whisk together the 2 cups flour, baking powder and salt.
In a separate large bowl, whisk together the melted butter, oil, sugar, eggs lemon zest, vanilla extract and milk. Whisk until the mixture looks even in color.
Make a well in the middle of the dry ingredients, then pour the wet ingredients into the well. Do a few stirs with a rubber spatula or wooden spoon, then whisk until incorporated, but stop whisking as soon as the mixture is evenly mixed.
In a separate small bowl, toss the raspberries with the 1 tablespoon of flour.
Carefully fold the raspberries into the batter using a rubber spatula or wooden spoon.
Spoon the batter into the prepared pan and smooth the top.
Bake in the preheated oven for 55-65 minutes, or until an inserted toothpick comes out clean or with a few crumbs. Check the bread around 40 minutes. If the top is already golden brown, tent a piece of aluminum foil overtop of the loaf and continue baking to prevent overbrowning.
Cool the loaf in the pan for at least 20 minutes, then carefully invert and continue cooling on a wire rack.