Prepare two round 8-inch cake pans by lining the bottoms with parchment paper circles
Preheat your oven to 350°F (175°C).
In a medium mixing bowl, whisk together: Gluten-free flour, Baking powder, Baking soda and Salt.
In a stand mixer fitted with the paddle attachment beat the softened butter and avocado oil together for about 1 minute. The mixture may look slightly lumpy or resemble cottage cheese — this is normal. Add the sugar and beat on medium speed for 3–5 minutes until the mixture becomes light, fluffy, and pale in color.
Add eggs one at a time, mixing well after each addition. Scrape down the sides of the bowl as needed to ensure everything mixes evenly. Mix in the blended strawberries and vanilla extract until fully incorporated.
With the mixer on low speed: Add about ? of the flour mixture, Add ½ of the sour cream, Add another ? of the flour mixture, Add the remaining sour cream, Finish with the final portion of flour. Avoid overmixing the cake batter, as this can make gluten-free cakes dense or gummy.
Divide the batter evenly between the prepared pans. Use a spatula to smooth the tops for even baking. Lightly tap the pans on the counter to release trapped air bubbles. Bake for 20–25 minutes.
Allow cakes to cool in the pans for 10–15 minutes. Let cakes cool completely before frosting.