Banana Ganache TartsPosted: March 23, 2014 Filed under: Desserts | Tags: banana, banana ganache, chocolate, dessert, ganache, mirror glaze 7 Comments
Here’s a very indulgent treat, just in time for Mothers Day.
I’m really rather pleased with the star of the recipe, the banana ganache. Looking at other online recipes, people SAY it’s banana ganache, but when you click on it, you find they’ve mixed it with chocolate or fruit or caramel or rum. Not that any of those aren’t delicious combinations, but I wanted something that captured the pure flavour of fresh banana, and here it is. Of course, as can be seen from the picture, I then proceeded to pour it ONTO chocolate and then slather it IN chocolate, but the ganache itself is wonderfully unadulterated and fresh-tasting.
This is one of my, what I like to call, Lego™ recipes. I take a brick from this recipe, and a brick from that recipe and click them together with some new bits and bobs to make a new recipe. In this case I’ve taken the mirror glaze recipe from the Sicilian Seven Veils Cake, and the chocolate pastry from the Midnight Meringue to make this very rich and delicious dessert. If you have some Crepes Dentelles biscuits, you could make the base out of the Feuilletine recipe (also from the Sicilian Seven Veils Cake) for a quick, no-bake recipe, or go cheap and cheerful with either cornflakes or rice crispies mixed with melted chocolate.
I’ve used a nifty trick to make individual servings by making a thin tray-bake and then using a flower-shaped pastry/biscuit cutter to cut out the un-glazed-but-set ganache. The mirror glaze is then poured over the top and makes for a seamless and wonderfully glossy finish.
I’m hoping some of you might try this for Mothers Day, but you can just as easily keep everything simple as a tray-bake. Another alternative is to use just the ganache either dipped in tempered chocolate or rolled in either cocoa or dessicated coconut to make bite-sized truffles. You could also use the ganache in/on a cake, but plan ahead, because it does need several hours in the fridge to firm up before it is spreadable.
Banana Ganache Tart
100g plain flour
15g cocoa powder
60g caster sugar
60g unsalted butter, cut into cubes
1 tbsp milk
- Preheat the oven to 200°C 180°C Fan.
- Grease and line with parchment a rectangular baking tin. You want something quite large, so the pastry and ganache layers will be thin. I used a roasting tin of dimensions 20cm x 30cm. If you’re not going to cut individual portions, a 24cm loose-bottom, spring-form cake tin is another option.
- In a food processor, mix flour, cocoa and sugar.
- Add butter, cut in small cubes. Blitz.
- Add the tablespoon of milk and blend again until mixture resembles coarse, damp sand.
- Press the mixture into the base of your tin. Keep the layer thin – no more than 5mm before baking – otherwise it becomes to clunky for a delicate dessert.
- Prick the pastry thoroughly with a fork and bake for 10 minutes.
- Check pastry for done-ness (always a little tricky with chocolate pastry, but it will be firm to the touch and have shrunk from the sides a little when filly baked). Return to the oven until fully baked if necessary.
- Allow the pastry to cool in the tin on a wire rack.
275g banana – about 3 ripe bananas
25ml syrup 
140ml double cream
400g white chocolate
45g unsalted butter
- Mash the bananas to a smooth puree. I’ve found the best way is to break them into pieces and then use an immersion/stick blender to get rid of all lumps. Alternatively, mash them by hand then pass through a sieve.
- Put the banana puree, syrup and cream into a small pan.
- Break the chocolate into pieces and put into a bowl.
- Bring the puree mixture to a boil, stirring continuously, then pour over the chocolate.
- Leave for 5 minutes to melt.
- Stir gently until thoroughly combined. Set aside to cool
- When the banana mixture has cooled to 35°C add the cubed butter and use the immersion/stick blender again to whisk it in. The combination of the butter and the vigorous whisking will help to emulsify and thicken the ganache.
- If making the tarts/tray-bake, pour the ganache over the chocolate base and set aside to cool. Cover lightly with a flat sheet of parchment only – using plastic film at this point will trap condensation which will then drip onto your ganache – ew.
- When completely cold, cover with film and chill in the fridge.
Chocolate Mirror Glaze
4 leaves (8g) gelatine
150ml double cream
225g granulated sugar
75g cocoa powder
NB If you’re making the tray-bake, halve these quantities. If glazing individual tartlet portions, you’ll need the full quantity.
- Soak the gelatine in plenty of cold water. I leave the sheets whole, as it is easier both to fish them out of the water and to shake off the excess water from them once hydrated.
- Put the rest of the ingredients into a saucepan and heat gently, stirring, to dissolve the sugar.
- Continue stirring and, once the sugar is dissolved, bring to the boil.
- Simmer for 3-4 minutes, until the mixture reaches a temperature of about 104°C.
- Remove from the heat and let the mixture cool for 5 minutes. Keep stirring as the base of the pan will still be very hot and might burn the mixture. If you’re glazing individual tartlets, pour the mixture into a jug and prepare your tartlets (see below).
- Leave to cool until the mixture reaches 50°C, then drain the gelatine and stir into the mixture until it is fully dissolved.
- Let the mixture cool further until just 35°C and is beginning to thicken and set.
- If you’re making the tray bake, pour the glaze over the cooled and chilled ganache and leave to set. Chill in the fridge. Otherwise, see below:
- Glazing individual tarts
- Select an appropriately-sized cutter. I used a flower-shaped cutter of diameter 8cm. Other shapes might include hearts or stars. This might sound small, but as already stated, the ganache is very rich, and anything larger is going to push the portion size toward sickly.
- Grease the cutter, inside and out, with a non-flavoured oil. Almond oil is very mild, personally I used grape-seed oil. The ganache is very sticky and the oil will help the cutter pass easily through and, more importantly, help it pass easily out again. NB: Be sure to clean and re-oil the cutter after each use.
- Use the cutter to cut out shapes and move them to a wire rack. Make sure they are evenly spaced out on the rack as this is where they will be glazed. If the cut tartlets are reluctant to come out of the cutter, run the point of a sharp knife around the edge of the cutter from the underside.
- If the glaze is still too warm, put the rack into the freezer to firm up the tartlets.
- When the glaze has cooled enough to pour, put the wire rack with the tartlets over a bowl wide enough to catch all the drips.
- Slowly pour the glaze over the tarts one at a time. Pour onto the centre of the tart and the glaze will spread smoothly across the surface and down the sides. Don’t rush this. If you have to go back and ‘patch’, then the glaze will not be smooth. It is better to glaze 3 or 4 tarts perfectly first time, than glaze them all in one go but have to go back and patch up the missed bits.
- The glaze that drips through the rack into the bowl can be re-used, provided it is done at once, before it has cooled too much. Set the rack aside and scrape the glaze back into the jug. Replace the rack over the bowl and continue glazing.
- Allow the glaze to cool, and chill thoroughly in the fridge until required.
 I used maple syrup because I had some, but any liquid sugar will do – honey, golden syrup, agave, etc.