To begin, preheat the oven to 350°F.
Prepare your cake pans by lining the bottom of three 6-inch round pans or two 8-inch round pans with parchment paper rounds. Ensure a nonstick surface by also spraying the parchment paper and sides of the pans. This step is crucial to prevent the cake from sticking.
Mix eggs, honey, yogurt, lemon zest, lemon juice, and almond extract in a large bowl until smooth and well combined.
In a separate bowl, whisk together almond flour, oat flour, poppyseeds, baking soda, and salt. Then, add these dry ingredients to the wet mixture and blend until smooth.
Divide batter evenly between pans, smooth tops with a spatula, and bake for 18-28 minutes (8-inch pans) or 25-35 minutes (6-inch pans). Test with a toothpick for doneness. Cool completely before frosting. Best to frost at room temperature or make a day ahead.
Create raspberry frosting: Blend ½ cup raspberries until smooth, strain to remove seeds, and set aside. In an electric mixer, whip softened butter, 4 cups powdered sugar, lemon juice, lemon zest, and 2 tbsp raspberry puree until well combined. Adjust sweetness with more powdered sugar if desired. Optionally, add 1 tbsp milk for creaminess.
Frost the cake by placing 1 tablespoon on the cake stand and spreading it. Invert a cake, add 1/2 cup frosting between layers, and top with halved raspberries. Smoosh them into the frosting for a seamless finish. Repeat for all layers, then frost the top and sides with the remaining lemon frosting. Enjoy!
Enhance the cake by garnishing it with fresh raspberries just before serving, ensuring their freshness.
After a day at room temp, refrigerate your cake for up to 7 days to keep it fresh. Ensure it's well-covered.