Preheat your oven to 175°C (350°F). Grease a 9x13-inch baking pan and line it with parchment paper for easy removal.
Step 2: Mix Dry Ingredients
In a large bowl, whisk together the flour, baking powder, baking soda, and salt. This ensures even distribution of the leavening agents.
Step 3: Combine Wet Ingredients
In another bowl, mix the melted butter, sugar, eggs, kefir, and vanilla extract. Stir until the mixture is smooth and well combined.
Step 4: Combine Wet and Dry Mixtures
Gradually add the dry ingredients to the wet mixture, stirring gently until no lumps remain. Avoid overmixing, as this can make the cake dense.
Step 5: Pour and Bake
Pour the batter into the prepared pan and spread it evenly with a spatula. Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
Step 6: Cool and Frost
Let the cake cool completely in the pan before adding any frosting, glaze, or decorations.
