Preheat the oven to 350°F. Brush the bottoms and sides of your cake pans with melted butter and line with parchment paper to prevent sticking.
Heat the milk in a medium saucepan until it just begins to simmer with bubbles forming around the edges. Remove from heat, add the Earl Grey tea bags, and steep for 30 minutes. Remove tea bags, squeezing out as much milk as possible.
Measure 12 oz (355 ml) of the tea-infused milk (top off with regular milk if necessary). Whisk in eggs, canola oil, and vanilla extract until combined.
In a stand mixer bowl fitted with the paddle attachment, combine cake flour, sugar, baking powder, salt, finely ground Earl Grey tea, and orange zest. Mix on low speed for 1 minute to blend.
With the mixer on low, add softened butter pieces gradually until mixture resembles cornmeal and can be squeezed to hold shape.
Slowly pour about 4 oz (1/2 cup) of the milk/egg mixture to moisten the dry ingredients and mix on medium speed for 2 full minutes until the batter is light and fluffy. Scrape the sides and bottom of the bowl.
Add the rest of the milk/egg mixture in three parts, mixing on low speed and scraping down the bowl after each addition. Stir the batter gently with a spatula to fully combine.
Divide the batter evenly among the prepared pans. Bake for 35-45 minutes, checking at 30-35 minutes with a toothpick for doneness. The cake should be springy and the toothpick should come out clean.
Firmly tap the pans on the counter to release steam and gently press down any domed tops. Cool in pans for 15 minutes, then run a palette knife around edges and turn out onto cooling racks. Wrap and chill for a few hours to firm up.
Puree fresh blackberries in a food processor and strain through a fine mesh sieve. In a saucepan, combine sugar and water without stirring and cook over medium heat until caramel turns a rich amber color. Remove from heat and whisk in the blackberry purée. If caramel seizes, gently reheat while whisking until smooth. Cool caramel for 10 minutes in the pan, then transfer to a jar to cool completely.
Combine egg whites, honey, and sugar in a heatproof bowl over simmering water. Whisk constantly until temperature reaches 160°F. Strain the mixture into a stand mixer bowl and whisk at medium speed until glossy, stiff peaks form and the bowl is cool to the touch.
Switch to paddle attachment and mix on low speed, gradually adding softened butter cubes a few at a time. The mixture may curdle but continue mixing until smooth and creamy.
Add salt and vanilla extract and mix until fully incorporated and the buttercream is satiny smooth.
Layer cake with honey buttercream, drizzle or spread blackberry caramel as desired. Decorate the cake with fresh blackberries, figs, and optional candied oranges to finish.
Notes
Use high-quality Earl Grey tea for the best flavor.
Allow the cake to chill for a few hours for easier slicing.