Instructions

Adjust oven rack to middle position and heat oven to 300 degrees. Grease 12-cup nonstick Bundt pan with baking spray with flour. Working in batches, grind 1½ cups freeze-dried strawberries in spice grinder into fine powder; transfer to small bowl and set aside. 
Using stand mixer fitted with paddle, beat 8 ounces softened cream cheese, 3 cups granulated sugar, 24 tablespoons softened unsalted butter, 1 tablespoon vanilla extract, and 1 teaspoon table salt on medium speed until pale and fluffy, 6 to 8 minutes, scraping down sides of bowl as needed. Add 6 room temperature large eggs, 1 at a time, and beat until combined. Scrape down bottom and sides of bowl, then beat on medium-high speed until light and airy, about 3 minutes. Reduce speed to low, add 3 cups cake flour, and mix until just combined. 
Transfer half of batter to medium bowl. Stir strawberry powder and ¼ teaspoon red food coloring, if using, into remaining batter in mixer bowl until fully combined. Using large portion scoop or spoon, drop alternating spoonfuls of plain batter and strawberry batter into prepared pan. Gently tap pan on counter to release air bubbles. 
Bake until cake is golden brown and wooden skewer inserted in center comes out clean, 1½ to 1¾ hours.
Let cake cool in pan on wire rack for 10 minutes. Whisk together ⅓ cup confectioners’ sugar and ⅓ cup heavy cream in medium bowl until fully combined. Flip cake onto wire rack set in rimmed backing sheet and brush exterior all over with heavy cream mixture. Let cool completely, at least 2 hours. Slice and serve. (Cake can be wrapped in plastic wrap and held at room temperature for 3 days.).