Preheat oven to 350°F (175°C). Lightly grease an 8x8-inch pan or line with parchment paper. This recipe yields a thin cake suitable to crumble into shooter glasses.

Dry ingredients

In a medium bowl whisk together the all-purpose flour, granulated sugar, brown sugar, baking powder, baking soda, ground cinnamon, and salt until evenly combined.

Wet ingredients

In a separate bowl whisk the egg, vegetable oil, vanilla extract, and buttermilk until smooth.

Combine batter

Pour the wet mixture into the dry ingredients and stir just until combined. Fold in the finely grated carrots, chopped nuts (if using), and raisins (if using). Do not overmix.

Bake

Spread batter evenly in the prepared pan and smooth the top. Bake in the preheated oven for 15–18 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs. The cake should be slightly springy on top.

Cool and crumble

Allow the cake to cool completely in the pan on a wire rack (about 30–40 minutes). Once cool, crumble the cake into fine crumbs using your hands or pulse briefly in a food processor. Measure out about 1/2 cup cake crumbs per 6 shooter servings (adjust as needed).

Cream Cheese Frosting (for shooter topping)

Beat cream cheese and butter

In a medium bowl, beat the softened cream cheese and softened butter together until smooth and creamy using a hand mixer or whisk.

Sweeten and flavor

Add the sifted powdered sugar and vanilla extract (and lemon zest if using). Beat until smooth and just spreadable. If the frosting is too thick for piping into shooters, add 1 teaspoon of milk or cream to loosen; if too thin, add a little more powdered sugar. Transfer frosting to a piping bag fitted with a small round or star tip, or a resealable plastic bag with a corner snipped off.

Assembly & Garnish

Prepare shooter glasses

Use 12 shooter glasses (1–2 oz each) or small clear glasses. Place about 1 tablespoon (roughly 15 ml) of crushed graham crackers or cake crumbs into the bottom of each glass to create a base layer.

Layer cake crumbs

Divide the crumbled carrot cake evenly among the shooter glasses, pressing lightly to create a compact layer about 1/2 inch thick (approximately 2 tablespoons cake crumbs per shooter).

Pipe frosting

Pipe or spoon about 1 tablespoon of cream cheese frosting on top of the cake layer in each shooter. Smooth the top lightly if desired.

Top with crumbs and garnish

Sprinkle a pinch of crushed graham crackers and a light dusting of ground cinnamon over each frosting. Finish each shooter with a small sprinkle of toasted chopped nuts and an optional mini carrot candy or candied peel perched on the rim.

Chill and serve

Refrigerate the assembled shooters for at least 30 minutes to allow the frosting to set and flavors to meld. Serve chilled. Store leftover shooters covered in the refrigerator for up to 3 days.