Prep the pan and oven: Heat oven to 325°F (165°C). Grease and line a 9x5-inch loaf pan or an 8-inch round cake pan with parchment, leaving an overhang for easy lifting.
Mix the wet ingredients: In a large bowl, whisk the oil and brown sugar until smooth. Add the eggs one at a time and whisk until glossy.
Stir in the vanilla, orange juice (or brandy), and mincemeat.
Combine the dry ingredients: In a separate bowl, whisk flour, baking powder, baking soda, salt, cinnamon, and allspice.
Bring it together: Add the dry mixture to the wet ingredients. Fold gently with a spatula until just combined. If using nuts, zest, or extra dried fruit, fold them in now.
Do not overmix.
Fill the pan: Scrape the batter into the prepared pan and smooth the top. Tap the pan lightly on the counter to release air bubbles.
Bake: Bake 55–70 minutes for a loaf, or 45–60 minutes for an 8-inch round, until the top is set and a toothpick comes out with a few moist crumbs. If browning too quickly, tent loosely with foil for the last 15 minutes.
Cool and finish: Cool in the pan 15 minutes, then lift out to a rack.
While warm, brush the top with warm brandy or orange juice. For a glossy finish, warm the apricot jam and brush over the top.
Rest before slicing: Let it cool to room temperature. For the cleanest slices and best flavor, wrap and rest at least 4 hours or overnight.