Prepare two 6-inch round cake pans by lining the bottoms with parchment paper. Lightly grease the sides for an easy release. Set the pans aside.

Preheat your oven to 325°F (163°C).

In the bowl of a stand mixer fitted with the paddle attachment, sift together the flour, cocoa powder, sugar, baking powder, baking soda, and sea salt. Mix briefly to combine.

In a separate measuring cup, combine the avocado oil, buttermilk, hot boiling water, and vanilla extract. Stir gently to ensure all liquids are incorporated.

With the mixer on low speed, slowly pour the wet ingredients into the dry mixture. Allow the mixer to run for about 30 seconds, just until the batter turns smooth. Avoid overmixing.

Scrape down the sides of the bowl with a spatula. With the mixer still on low, add the eggs, one at a time. After each egg, mix until the batter is silky and evenly combined, about 30-60 seconds.

Divide the batter evenly between the two prepared cake pans. Tap each pan firmly on the counter a few times to release any air bubbles trapped in the batter.

Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted in the center comes out clean with only a few moist crumbs.

Remove the cakes from the oven and allow them to cool for about 15 minutes while still in their pans. Gently run a knife along the edges and carefully invert each cake onto a cooling rack to cool completely.

Place the chopped white chocolate in a heatproof bowl.

In a small saucepan, heat the heavy cream over medium heat until it’s hot but not boiling look for small bubbles forming around the edges. Pour the hot cream over the white chocolate and let it sit for 2-3 minutes without stirring.

Once the chocolate has softened, stir the mixture gently until smooth and fully melted. Add the vanilla extract and a pinch of sea salt to enhance the flavor. Allow the ganache to cool to room temperature. If needed, place it in the refrigerator to speed up the cooling process.

Once the ganache has cooled, transfer it to a stand mixer with a whisk attachment. Whip the ganache on low speed, gradually increasing to medium-high. Add the softened butter one tablespoon at a time, allowing each addition to fully incorporate before continuing.

When the butter is completely mixed in, sift the powdered sugar into the bowl and whip on high speed until the cream filling is light, fluffy, and airy.

Fold in the crushed Oreo cookie crumbs, ensuring they’re evenly distributed throughout the cream. If the filling begins to soften, place it in the refrigerator for a few minutes to firm up before continuing.

If you’d like to create a four-layer cake, carefully slice each cake horizontally using a serrated knife. Otherwise, leave them as two layers.

Place a small dollop of the cream filling on a cake board to hold the cake securely. Position the first cake layer on the board.

Spread about ½ cup of the Oreo cream filling evenly across the top of the first cake layer using an offset spatula. Repeat this process with the remaining cake layers, stacking one on top of the other.

Using the remaining cream, apply a thin layer around the sides and top of the cake to create a crumb coat. This layer will seal in any loose crumbs for a smooth finish. Chill the cake in the refrigerator for 10-15 minutes to set the crumb coat.

Once chilled, apply a final layer of the Oreo cream filling over the cake, smoothing it out with an offset spatula for a clean and polished finish.

Decorate the cake as desired use additional Oreo crumbs, whole cookies, or decorative piping for an elegant touch.

Store the finished cake in the refrigerator until ready to serve. If the cream becomes too firm, let the cake sit at room temperature for a few minutes before slicing.