I’ve made various flavoured vodkas and gins (and limoncello). Not tried a brandy base, mainly vodka based (infuse with juniper/coriander/rosemary/lemon peel and star anise and you get a very nice gin), lemon and orange peel in vodka for a week, then add some sugar and wash through with more vodka does a decent limoncello. A real party winner was hibiscus and pomegranate molasses vodka (reduced the hibiscus flowers in water and cane sugar with pomegranate to a thick syrup then strained and added to good vodka).
Next up will most likely be a green tea and lemon gin.