01 - Preheat oven to 350°F. Grease and line a 9x5-inch loaf pan with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, and poppy seeds until well blended.
03 - In a large bowl, beat butter and sugar with an electric mixer until light and fluffy, approximately 2-3 minutes.
04 - Add eggs one at a time, mixing thoroughly after each addition. Blend in lemon zest, lemon juice, sour cream, milk, and vanilla extract until fully incorporated.
05 - Gradually fold the dry mixture into the wet ingredients until just combined. Avoid overmixing to preserve texture.
06 - Toss fresh raspberries with 1 tablespoon flour to prevent sinking, then gently fold into the batter.
07 - Pour batter into the prepared loaf pan and smooth the top evenly with a spatula.
08 - Bake for 50-60 minutes until a toothpick inserted in the center comes out clean. Tent loosely with foil after 35 minutes if the top browns too quickly.
09 - Allow the loaf to cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.
10 - Whisk powdered sugar and lemon juice until smooth. Drizzle over the completely cooled loaf before serving.