Roasted Strawberry Purée:

1. Preheat oven to 350ºF. Place chopped strawberries in a 8-9" square baking dish (preferably glass/pyrex) and sprinkle sugar on top. Toss to coat strawberries with sugar. Bake in preheated oven for 15 minutes. The strawberries should be soft and juicy when done. 
2. Transfer strawberries to a blender, being sure to scrape up as much of the fruit/juice as possible from the pan. Add buttermilk to blender and blend mixture until smooth. Transfer to a clean bowl and allow to cool to room temperature while making strawberry jam.

Strawberry Jam:

1. In clean blender, combine strawberries and sugar and blend until smooth. Transfer to a small saucepan and bring to a simmer over medium-low heat. Cook, stirring often with a spatula and adjusting heat as needed to retain a simmer, until the mixture has reduced to about 1-2 tablespoons worth of jam (this takes about 5-10 minutes on my stove).
2. Strain jam through a fine-mesh sieve into a small bowl, pressing as much of the jam through as possible. Use a spatula to push the jam into a small clump, cover directly over the surface with plastic wrap, and transfer to the refrigerator to chill completely while making cake.

Strawberry Cake

1. Keep oven at 350ºF. Butter two 4" wide x 2" high round cake pans. Line the bottoms with parchment rounds and dust the sides with gluten-free flour, tapping out any excess. 
2. Sift the flour, baking powder, salt, and baking soda into a medium bowl. Whisk together well after sifting.  
3. In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, sugar, and vanilla bean seeds until light and fluffy, scraping down the bowl and beater as needed. Add the egg and beat in until fully and smoothly incorporated, again scraping down bowl/beater as needed. With the mixer on low speed, slowly stream in the room temperature strawberry purée. Add the vanilla extract and continue to beat until the liquid ingredients are fully incorporated, scraping down as necessary. The mixture may appear to separate after adding the purée; this is okay!
4. Add the dry ingredients to the wet and mix in on lowest speed until only a few streaks of flour remain. Finish mixing together by hand just until all ingredients are evenly incorporated.
5. Divide the batter evenly between the two prepared cake pans. Smooth surface out as best as possible with a spatula, and then bang each cake pan on the counter several times to eliminate any air bubbles before baking. 
6. Transfer pans to the preheated oven and bake for about 30 minutes, until a toothpick inserted into the center of the cake comes out clean or with just a few moist crumbs. Cool cakes in pans over a wire rack for 20-30 minutes, and then remove from pans and place directly on wire racks to finish cooling. Once cool, wrap cakes tightly in plastic wrap until ready to frost. 

Strawberry Cream Cheese Frosting

1. In the clean bowl of a stand mixer fitted with the paddle attachment, beat together the cooled strawberry jam, butter, and cream cheese on medium-low speed just until smoothly combined, scraping down the bowl and beater as needed. Add the confectioner's sugar and beat in on medium-low until incorporated. Add the milk/cream, vanilla, and salt, and continue to beat just until the frosting is smooth, again scraping down the bowl and beater as needed. If necessary, use a spatula to finish mixing the frosting by hand and press out any air bubbles. 

Assembling and Decorating

1. Remove parchment rounds from bottom of cake. Use a large serrated knife to level both cake layers by slicing off the domed tops. 
2. Place one cake layer cut side-up on a plate or cardboard round set on top of a rotating cake stand. Use an offset spatula to add an even layer of frosting on top. Place the second cake layer over the first, bottom-up. Apply a thin layer of frosting (crumb coat) to the exterior of the cake to fill in any gaps between the layers and seal in crumbs. Transfer cake and frosting to the refrigerator to chill for about 10 minutes.
3. Add a second layer of frosting to the cake, this time being sure to create a smooth, even finish all around. Transfer remaining frosting to a piping bag fitted with tip of choice (I used Ateco #846) and pipe a border of frosting around the perimeter of the cake. Top with fresh strawberries in the center and garnish with sugar pearls as desired. 
4. This cake should be kept chilled until ready to serve. Cover any leftovers with plastic wrap placed directly over the surface of the cake and, if possible, store in an airtight container.