To ensure your cakes won't stick, preheat the oven to 350F (175C) and grease three 8” round baking pans with baking spray while lining the bottoms with parchment paper.
In a spacious mixing bowl, blend cake flour, sugars, baking powder, baking soda, and salt for a uniform mixture.
Blend in the browned butter with an electric mixer on low-speed until fully combined.
Start by whisking buttermilk, eggs, and vanilla in a separate bowl. Slowly pour this mixture into the flour blend. Remember to pause halfway and at the end to scrape the sides and bottom of the bowl, even if you spot small lumps in the batter.
Incorporate pecans seamlessly by stirring.
To achieve perfection, evenly distribute the batter among the prepared baking sheets. Place them in the center rack of a 350°F oven and bake for 30 minutes, or until a toothpick inserted into the center emerges clean or with only moist crumbs.
After baking, it's essential to let the cakes cool in their pans for 15 minutes. To release them, gently run a knife along the cake's edge, and then carefully invert them onto a cooling rack for complete cooling. Remember, the cakes must be entirely cool before you start decorating.