Preheat the oven to 350 degrees F. Grease bottom and sides of one 9 x 5-inch loaf pans; dust with flour, tapping out excess.

In a medium bowl, sift together flour, baking powder and salt; set aside.

In a large bowl, whisk together the buttermilk, sugar, eggs, lemon zest, vanilla and oil. Slowly whisk the dry ingredients into the wet ingredients.

In a separate bowl, mix 1 cup of raspberries with the remaining tablespoon of flour, and fold them very gently into the batter. Pour into prepared loaf pan.

In a small blender, blend the lemon juice, remaining ¼ cup raspberries, framboise liqueur, and sugar. Blend until smooth. Strain through a fine mesh strainer to remove seeds and drizzle lightly on top of the batter. Use a toothpick to swirl into the batter.

Bake 50 to 55 minutes, or until a toothpick inserted in the center of the loaf comes out clean. Let cool in the pans for 10 minutes before removing loaf to a wire rack on top of a baking sheet.

While the loaf is cooling, make the lemon syrup in a small saucepan over medium heat. Stir together the lemon juice and sugar until the sugar is completely dissolved. Once dissolved, continue to cook for 3 more minutes. Remove from the heat; set aside.

Use a toothpick to poke holes in the tops and sides of the warm loaf. Brush the top and sides of the loaf with the lemon syrup. Let the syrup soak into the cake and brush again. Let the cake cool completely.