Two ways to experiment
You can bring similar impressions together: for example, a nutty-tasting coffee with a pastry that also has nutty notes. Or seek a contrast, such as a livelier coffee with a creamy dessert. These are ideas for your own tasting, not scientifically guaranteed pairing rules.
Start with a cake you already enjoy. Choose a coffee to go with it and first taste each separately. Only then alternate a small bite and a sip. This lets you notice what the combination changes compared with its individual components.
Sweetness changes the next sip
After a very sweet bite, the same coffee can seem different from before. Notice whether it feels more bitter, fresher or less balanced to you. You do not need to correct that impression immediately with extra sugar. Perhaps you would prefer a different proportion of coffee in your milk drink or a less sweet pastry.
Drink some water between tastes and take short breaks. Many quick bites make comparison harder. The aim is to find a pleasant combination, rather than taste as much as possible. Half a portion to share may be quite enough.
Three possible directions
With a chocolate dessert, try a coffee with a cocoa-led profile. A clear filter coffee can be interesting with fruit cake, and a creamy milk drink with spiced pastry. Use these suggestions as ideas for comparison: taste separately first, then together. What matters is how this particular cake and coffee interact, rather than whether their descriptions look like a good match on paper.
If you dislike a pairing, your perception is not at fault. Perhaps the cake overwhelms the coffee, or perhaps the contrast bothers you. Briefly note what happens and change just one side next time. You will learn more that way than by searching for a supposedly perfect universal list.
Consider temperature and portion
Very hot coffee can dominate the first comparison. Let it reach a comfortable drinking temperature. Likewise, a dessert straight from the fridge can give different impressions a little later. Keep conditions as similar as possible for a comparison without turning it into a laboratory exercise.
Portion size matters too. A small, intense espresso beside a large, sweet slice has a different effect from a long milky coffee. Choose for your moment of enjoyment rather than whichever pairing looks more impressive in a photo.
Ingredients take priority
Check allergens and personal intolerances against the specific products. Nutty tasting notes in coffee do not automatically mean added nuts; cakes or flavoured drinks, however, may actually contain them. Ask rather than deriving an ingredient list from an aroma description.
On your next café visit, you can ask the team for a suitable combination from the current selection. The best suggestion remains something you can test: you taste and decide for yourself. A lovely pairing needs no tasting jargon, just a little attention and room for the next bite.