Preheat your oven to 350°F (175°C).
In a large bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, mix the melted butter, buttermilk, eggs, and vanilla extract.
Combine the wet and dry ingredients, folding in the raspberries and bacon.
Grease a donut pan and fill each cavity about two-thirds full with the batter.
Bake for 12-15 minutes, until the donuts are golden brown.
Allow the donuts to cool in the pan for 5 minutes, then transfer to a wire rack.
In a small saucepan, heat the maple syrup over low heat until warm.
Drizzle the warm maple syrup over the cooled donuts and top with additional crumbled bacon.