Preheat your oven to 350°F (175°C) and prepare a 9×5-inch loaf pan by greasing it with butter or lining it with parchment paper.

In a large mixing bowl, whisk together the flour, light brown sugar, granulated sugar, baking soda, and salt. Stir until well blended and set aside.

In a separate bowl, melt the unsalted butter and let it cool slightly. Whisk in the egg, buttermilk, canola oil, and vanilla extract.

Pour the wet mixture into the dry ingredients and gently mix until just combined, keeping the batter lumpy.

Toss the raspberries with flour to help prevent them from sinking. Gently fold them into the batter without crushing.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake for 45 minutes to 1 hour, until the top is golden brown and a toothpick comes out clean or with few moist crumbs.

Remove from oven, let cool in pan for 15 minutes, then transfer to a wire rack to cool completely.