Preheat oven to 325°F (170°C).

In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugar at medium speed until light and fluffy, about 5 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Beat in vanilla. (Mixture may look slightly broken, but batter will come together.) Transfer half of butter mixture (about 402 grams) to a medium bowl.

In a small bowl, whisk together 1¼ cups (156 grams) flour, ¼ teaspoon (1.25 grams) baking powder, and ¼ teaspoon salt. Fold flour mixture into half of butter mixture alternately with buttermilk, beginning and ending with flour mixture, folding just until combined. Set aside.

In another small bowl, whisk together remaining 1 cup (125 grams) flour, remaining ¼ teaspoon (1.25 grams) baking powder, and remaining ¼ teaspoon salt. In another small bowl, stir together Roasted Strawberry Purée and food coloring. Fold flour mixture into remaining butter mixture alternately with strawberry mixture, beginning and ending with flour mixture, folding just until combined.

Spray a 10-cup Bundt pan with cooking spray. Using a pastry brush, spread any excess spray evenly in pan, blotting brush with a paper towel as needed, and lightly flour pan, tapping any excess out to make a very thin layer.

Spoon plain and strawberry batters into separate large pastry bags; cut a ½-inch opening in tips. Pipe random small and medium dollops of batter in a ring in bottom of prepared pan. Repeat procedure, piping strawberry batter on top of vanilla batter and vanilla batter on top of strawberry batter to create a checkerboard-like pattern until all of batter is used up. Using a butter knife, swirl batters using a figure-8 motion, being careful not to touch bottom and sides of pan. Firmly tap pan on a kitchen towel-lined counter several times to settle batters and release any air bubbles.

Bake until a wooden pick inserted in center comes out clean, 52 to 58 minutes, rotating pan halfway through baking and loosely covering with foil during final 5 to 6 minutes of baking to prevent excess browning. Let cool in pan for 10 minutes. Invert cake onto a wire rack, and let cool completely.

Transfer cooled cake to a serving plate, and spoon Buttermilk Glaze on top. Garnish with strawberries, if desired. Refrigerate in an airtight container for up to 5 days; let come to room temperature before serving.