Preheat the oven to 350°F.
Butter and flour a 9"x5" or 8"x4" loaf pan.
Use your food processor or blender to puree the berries, then strain the puree through the fine mesh sieve into a 1 cup measuring cup. You will have about one quarter cup or a little more.
1 cup raspberries, washed
Sift together the dry ingredients (flour, baking powder, baking soda, salt) into a medium sized bowl.
1 ½ cup (195 grams or 6.9 ounces) bleached all-purpose flour, ½ teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon salt
Cream the butter and sugar together until light and fluffy. If using a stand mixer, this will take about 5 minutes on medium speed, longer if using a hand mixer.
1 stick (8 tablespoons or 113 grams or 4 ounces) unsalted butter, softened plus more for flouring the pan, 1 ¼ cup (250 grams or 8.8 ounces) granulated sugar
Add the eggs one at a time, beating for a minute after each addition and scraping down the bowl as necessary.
2 large eggs
Add the raspberry liqueur or vanilla and beat for a minute.
1 teaspoon Chambord (or other raspberry liqueur) or vanilla
Add approximately one half of the dry ingredients and mix on low speed until they are just incorporated.
Add enough buttermilk to the measuring cup to measure a total of three quarters cup (i.e. about one half cup of buttermilk or slightly less). Scrape down the bowl.
½ cup buttermilk
Add the remaining dry ingredients and mix until just barely incorporated.
Pour the batter into the prepared pan, even out the batter and give the pan a few thwacks on the counter to remove any air bubbles.
Bake the cake for about 45 to 50 minutes, until the top has started to brown and a toothpick inserted into the center comes out clean.
Cool in the pan for 10 minutes, and then invert and transfer to a cooling rack.