Preheat the oven to 350° F. Line two quarter sheet pans with parchment paper and coat with non-stick spray (**see note). Alternatively, use two 13 x 9-inch baking pans. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, combine the softened butter and sugar. Beat on low for a minute just to combine the butter and sugar. Scrape down the sides and turn the speed up to medium high. Beat for 2 to 3 minutes or until the butter is lightened in colour and fluffy.
Turn the mixer down to low and add the almond extract and vegetable oil along with one egg. Mix until the egg is fully incorporated, scraping down the sides as needed. Add the remaining eggs, one at a time, beating until fully combined. Once all the eggs have been added, turn up the speed to medium and beat for another minute until the mixture is thick, fluffy, and fully emulsified. Turn off the mixer.
Meanwhile, in a separate bowl combine the flour, almond flour, salt, baking powder, and baking soda. Whisk together until there are no lumps, then set aside.
Turn the mixer back on low. Add one third of the flour mixture and mix just until the flour is mostly incorporated. Pour in half the buttermilk mixture and continue beating until it is mostly incorporated. Stop the mixer and scrape down the sides. Repeat by adding another third of the flour followed by the remainder of the buttermilk. Add the last of the flour and mix on low just until the batter is fully combined.
Use a spatula to scrape down the sides of the mixing bowl and make sure there are no streaks of unmixed butter in the batter. Divide the cake batter between the pans and smooth the tops. Bake for 22 to 25 minutes until a toothpick comes out clean and the top springs back when touched. Let the cakes cool for 5 minutes then turn out onto a rack to cool completely.
In a food processor or blender, purée the raspberries. Transfer the raspberry purée to a fine mesh strainer set over a mixing bowl. Use a spatula to work the raspberry purée through the strainer to extract the purée from the seeds. Discard the seeds. You should have about half a cup of purée.
In a stand mixer, fitted with a paddle attachment, whip the softened butter. Beat the butter on medium for about 5 minutes until it’s lightened in colour and fluffy. Add half the icing sugar and mix on low just until combined. Add 4 tbsp of the raspberry purée and mix on low to combine.
Scrape down the sides of the bowl and add the remaining icing sugar. Continue beating on low to combine. Add another 3 to 4 tbsp of raspberry purée to make a soft buttercream that will spread and pipe easily.
Use a 3-inch cutter to cut out 12 circles from each sheet pan for a total of 24 circles. This will make either 12 two-layer cakes or 8 three-layer cakes. I find it easier to assemble and frost these as two-layer cakes.
Transfer some of the butter cream to a piping bag fitted with a wide round tip. For each layer, pipe a ring of buttercream around one of the cake circles. Use a spoon to spread the buttercream and make a well to hold the jam. Spoon a little of the jam into the well. Top with another cake circle pressing gently to seal. If making three-layer cakes, add another layer.
Transfer the filled layers to a baking sheet and place in the freezer. This will make frosting the outside of the cakes much easier. When the cakes are frozen, remove from the freezer and use an offset spatula to frost the outside and tops of the cakes. I find it easiest to hold the cakes by the top and bottom to spread the buttercream around the outside of the cake. Once the sides are done, you can frost the top.
Transfer the cakes to a serving platter and garnish with fresh flowers. Enjoy!