Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a fluted tube pan (such as Bundt®).
Step 2
Pat blueberries dry and place into a plastic bag. Toss with 1 1/2 teaspoons flour until all berries are dusted. Set aside.
Step 3
Combine 2 1/2 cups flour almond flour baking powder and salt in a medium bowl; stir with a fork until well blended.
Step 4
Combine sugar and butter in the bowl of a stand mixer. Cream together on high speed until light and fluffy about 4 minutes. Reduce speed to low; add eggs 1 at a time beating after each addition and scraping the bowl as needed.
Step 5
Mix in about 1/3 of the flour mixture followed by 1/2 of the buttermilk beating after each addition. Repeat ending with the final 1/3 of the flour mixture. Add lemon curd lemon zest and vanilla extract; beat until just combined. Turn off the mixer and fold in blueberries.
Step 6
Pour batter into the prepared pan cleaning the mixer bowl and beater with a scraper. Tap the tube pan lightly to remove any pockets of air.
Step 7
Bake in the preheated oven until a toothpick inserted into the center of the cake comes out clean 55 to 65 minutes. Allow the cake to cool completely in the pan on a wire rack about 30 minutes. Turn out onto a decorative plate.
Step 8
Stir powdered sugar lemon juice lemon zest and salt together in a microwave-safe glass bowl for the glaze. Place butter on top of the glaze and microwave until the mixture bubbles and the butter is melted about 1 minute. Whisk until smooth. Allow glaze to cool for about 15 minutes; pour over cake. Garnish with blueberries if desired.