Preheat oven to 350°F. Coat an 8" round cake pan with non-stick cooking spray (bottom and sides).
Place flour, granulated sugar and salt in a large mixing bowl. Cut in chunks of COLD butter, using a pastry blender or 2 knives or forks, until the butter/crumbs are about the size of peas. Measure out 1/2 cup of this crumb mixture and set aside to use as crumb topping later (set aside).
To the mixing bowl with remaining flour mixture add the baking powder, baking soda, buttermilk, lemon juice, and egg. Beat on medium speed with a mixer until well blended. Gently STIR in fresh raspberries until fully combined with batter. Spoon batter into the prepared (sprayed) cake pan. Gently spread to cover bottom of pan.
Take the reserved flour/crumb mixture and add lemon zest and juice to it. Combine these ingredients with a fork until crumbly. Sprinkle this mixture over the top of the cake batter, until top of cake is covered.
Bake cake on center rack of preheated 350°F oven for 25-30 minutes or until it is light golden brown on top and cake springs back with touched lightly in the center (mine took 30 minutes). Remove cake pan to a wire rack to cool to room temperature. Slice into 8 wedges, and garnish cake with fresh raspberries and a mint sprig, if desired. ENJOY!
Raspberry Lemon Crumb Cake https://www.thegratefulgirlcooks.com/raspberry-lemon-crumb-cake/