Step 1
Preheat the oven to 350 degrees F (175 degrees C). Line a 12-cup muffin tin with paper liners.
Step 2
Whisk together 1 1/2 cups flour baking powder baking soda and salt in a small bowl.
Step 3
Cream together sugar and butter until light and fluffy. Beat in eggs 1 at a time making sure to thoroughly combine after each addition. Mix in lemon zest and vanilla extract. Stir in 1/2 of the flour mixture until just combined. Add in the sour cream and lemon juice stirring until just combined. Add in the remaining flour mixture and stir to combine.
Step 4
Place raspberries in a small bowl. Sprinkle with 1 1/2 teaspoons flour and and toss to coat. Gently fold raspberries into the batter. Spoon batter into the prepared muffin cups filling each 3/4 full.
Step 5
Bake in the preheated oven until a toothpick inserted into the center comes out clean 20 to 23 minutes. Cool in the tin for 5 minutes. Transfer to a wire rack and let cool completely about 20 minutes.
Step 6
Place raspberries for frosting in a small saucepan and cook over medium heat until they burst and release their juices 5 to 10 minutes. Pour raspberries into a fine mesh sieve set over a medium bowl and use the back of a wooden spoon to press and extract approximately 1/3 cup juice from the berries. Discard seeds and allow juice to cool completely.
Step 7
Beat butter in a large bowl with an electric mixer until light and fluffy. Beat in powdered sugar 1 cup at a time until incorporated. Mix in 1/3 cup raspberry juice lemon juice lemon zest and salt; beat until combined. Pour in heavy cream and beat until frosting is light and fluffy about 2 minutes.
Step 8
Frost cooled cupcakes and top with additional raspberries if desired.