Step 1: Make the Lemon Cake.

Butter a 9-inch cake pan.

Preheat the oven to 300°F (150°C).

In a small bowl, whisk together the cake flour, baking powder, baking soda, and salt.

In a large bowl, cream together the softened butter and sugar until light and fluffy.

Add the egg and beat well.

Beat in the vanilla and lemon extracts.

Add half of the dry ingredients to the wet ingredients. Mix until just combined.

Add the buttermilk. Beat until combined.

Add the remaining dry ingredients. Mix just until combined. Don’t overmix.

Pour the batter into the prepared pan. Smooth out the top.

Bake in the preheated oven until lightly browned and a toothpick inserted in the center comes out clean, about 30 minutes.

Cool completely before making the trifles.

Step 2: Make the Sweetened Whipped Cream.

In a medium bowl, whip the cold heavy cream, vanilla bean paste (or vanilla extract), and maple syrup (or sugar) until medium-stiff peaks form.

Step 3: Assemble the Trifles.

Slice half of the cooled lemon cake into small cubes.

Place a few of the cake cubes in the bottom of a half-pint (8-ounce) jam jar.

Add a dollop or two of the whipped cream.

Drop in a layer of blueberries.

Spread a spoonful of lemon curd on top.

Repeat the layers once more: cake, whipped cream, blueberries, lemon curd.

Do the same with the remaining jam jars.

Step 4: Serve or Chill.

Serve immediately or store, covered, in the refrigerator for a few hours