Step 1

Preheat: Preheat oven to 350°F (177°C). Grease and flour 2 (8 x 8-inch) square baking pans.

Step 2

Mix batter: In a large bowl, add non-dairy milk, coconut oil, molasses, applesauce, coconut sugar, ground flax, cinnamon, ginger, nutmeg, cloves, baking powder, baking soda, and salt (see note 3). Use an electric mixer to mix until well combined. Add flour and mix until the last streak of flour is incorporated (don't overmix). Divide the batter into the prepared pans.

Step 3

Bake cakes: Bake cases until a toothpick comes out clean from the middle of the cake, 30 to 35 minutes. Let cool for 30 minutes in the pan, then transfer to a cooling rack to cool completely. If making cakes in advance, wrap in plastic and store at room temperature for up to 1 day (or, wrap plastic with another layer of tinfoil, then transfer to a freezer bag and freeze for up to 1 month).

Step 4

Mix dough: Add flax and water to a large bowl. Use an electric mixer to mix until well combined. Add coconut oil, molasses, coconut sugar, cinnamon, ginger, nutmeg, cloves, baking soda, baking powder, and salt. Mix until well combined. Add flour and mix until the last streak of flour is incorporated. (If the mixer is having trouble mixing in the flour, use a wooden spoon).

Step 5

Chill dough: Wrap dough tightly with plastic and put in the fridge for 20 minutes. Once dough is chilled, use a lightly floured surface to roll dough slightly thicker than ⅛-inch. Set out a knife, scalloped pastry wheel and toothpicks.

Step 6

Preheat oven: Put the racks in the upper- and lower-thirds of the oven; preheat to 350°F (177°C).

Step 7

Cut out cookies: Roll the dough out on a lightly floured surface, until it is just barely thicker than ⅛-inch. Use a scalloped pastry wheel and/or knife to cut: 25 (1½ x 1½-inch) squares, 1 (2 x 3-inch) rectangle, 2 (¼ x 3-inch) rectangles, 1 (¼ x 4½-inch) rectangle, and 4 (¼ x 6½-inch) rectangles (see note 4).

Step 8

Bake cookies: Carefully arrange the cookies on 2 parchment lined baking sheets. Bake until golden brown, about 12 minutes, rotating sheets half way. Let cool completely on the baking sheets. Cookies can be made 1 day in advance, and stored in an airtight container at room temperature.

Step 9

Reduce aquafaba: Add aquafaba to a small saucepan over medium-low heat. Simmer until it’s reduced to ½ cup of liquid. Transfer to a medium bowl to cool.

Step 10

Melt chocolate: Add chocolate to a small bowl. Microwave the chocolate in 20 second intervals, stirring in between, until melted (or alternatively, use a double boiler). Let the chocolate cool so it is no longer hot (but is just warm enough to be in liquid state).

Step 11

Whip aquafaba: Use an electric mixer to whip the cooled aquafaba on high speed, until it resembles whipped egg whites, 1 to 2 minutes.

Step 12

Whip coconut cream: Scoop out coconut cream into a large bowl. Use an electric mixer to whip the coconut cream until fluffy. Drizzle in melted (cooled) chocolate and vanilla. Whip until thick and fluffy. Add aquafaba and beat until fully incorporated.

Step 13

Use or refrigerate: The consistency of the buttercream will vary by the temperature in your kitchen. If it’s on the soft side or if not using right away, cover bowl with plastic wrap and set aside in the fridge. Once chilled, buttercream will stiffen and will need to soften up on the counter slightly (and potentially need to be re-whipped) before spreading on the cake.

Step 14

Cut cakes: Cut 1 cake in half to form 2 rectangles. Cut the remaining cake on the diagonals to form 4 even triangles (from 1 cake).

Step 15

Assemble base: Place 1 of the rectangles on a flat work surface. Spread a layer of buttercream on top, then stack with the remaining rectangle. Spread a layer of buttercream on top.

Step 16

Make roof: Add 1 triangle at a time on top of the rectangle base, spreading buttercream between each layer to adhere them. You will need to use 3 out of 4 of the triangles to form the roof (the 4th is extra, for snacking).

Step 17

Frost the outside: Use the remaining buttercream to frost the outside of the cake (all sides and the full roof). Make sure the buttercream is a thick consistency, and if starts to warm, place the icing in the fridge to harden (you can also place the frosted cake in fridge before adding gingerbread pieces).

Step 18

Decorate: Decorate the gingerbread cookies, if desired. Press the gingerbread windows, doors, trim into the buttercream to adhere. For the roof, start with the bottom layer of "shingles", pressing them down one at a time. Overlap the "shingles" as you work up to the top of the roof. Add any remaining decorations. The cookies will soften on the cake (a good thing!) so aim to assemble at least 1 hour before serving. Extras keep at room temperature for 2 days.