- Preheat oven to 350F (175C). Grease and flour a 9x13 inch baking pan. 
- In a large bowl, whisk together flour, sugar, baking powder, and salt. 
- Add softened butter and milk to the dry ingredients. Mix on low speed until just combined. 
- Add eggs and vanilla extract. Beat on medium speed for 2 minutes until smooth and creamy. 
- Gently fold in freeze-dried strawberry powder until evenly distributed. 
- 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. 
- To make the frosting, beat softened butter in a large bowl until smooth and creamy. 
- Gradually add powdered sugar, beating until light and fluffy. 
- Add milk and strawberry powder. Beat until well combined. 
- Frost the cooled cake and decorate as desired. 
- For a more intense strawberry flavor, increase the amount of freeze-dried strawberry powder. Cake flour can be substituted for all-purpose flour for a more tender crumb. For vegan option, substitute plant-based butter, milk, and egg replacements.