- Preheat oven to 350F (175C). Grease and flour a 9x13 inch baking pan. 
- In a medium bowl, whisk together flour, baking powder, baking soda, and salt. 
- In a large bowl, cream together butter and sugar until light and fluffy. 
- Beat in eggs one at a time, then stir in vanilla. 
- In a small bowl, combine buttermilk and freeze-dried strawberry powder. 
- Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk mixture, beginning and ending with the dry ingredients. Mix until just combined. Do not overmix. 
- Pour batter into the prepared pan and spread evenly. 
- Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean. 
- Let cool in the pan for 10 minutes before inverting onto a wire rack to cool completely. 
- Frost with desired frosting (cream cheese frosting or strawberry buttercream recommended). 
- Optional Tips: For a more intense strawberry flavor, add 1/2 teaspoon of strawberry extract to the batter. Buttermilk can be substituted with milk mixed with 1 tablespoon of lemon juice or vinegar. For a gluten-free version, replace all-purpose flour with a gluten-free all-purpose flour blend.