Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, and line the bottoms with parchment paper for easy removal.
In a mixing bowl, cream together the cannabis-infused butter, unsalted butter, and granulated sugar until light and fluffy.
Beat in the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract.
In a separate bowl, sift together the all-purpose flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, alternating with the whole milk, beginning and ending with the flour mixture. Mix until just combined, being careful not to overmix.
Divide the cake batter evenly between the prepared cake pans and smooth the tops with a spatula.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cakes from the oven and let them cool in the pans for 10 minutes before transferring them to a cooling rack to cool completely.
Meanwhile, prepare the Cannabutter Vanilla Buttercream Icing. In a mixing bowl, beat the softened cannabis-infused butter until creamy.
Gradually add the powdered sugar, one cup at a time, beating well after each addition until smooth and creamy.
Stir in the vanilla extract. If the icing is too thick, add whole milk, one tablespoon at a time, until desired consistency is reached.
Once the cakes are completely cooled, frost the top of one cake layer with a generous amount of Cannabutter Vanilla Buttercream Icing. Place the second cake layer on top and frost the top and sides of the cake with the remaining icing.
Decorate the Weed Birthday Cake as desired with additional sprinkles, candles, or decorations.
Slice and serve your Weed Birthday Cake and enjoy the celebration!