I just tried the Flourless Brownies recipe and it didn't work. It was oozing out the butter on the edges while cooking, so that was not pleasant. I think the ratio of 225 grams of butter may not be right? Also the brownies don't hold the shape, they are too runny and this looks rather like a loose paste. I am tasting really too much melted butter. I am a bit disappointed.
Nigella's Flourless Chocolate Brownies With Hot Chocolate Sauce (from NIGELLA EXPRESS) are made with a combination of melted butter, melted dark (bittersweet) chocolate, eggs and ground almonds (almond meal). As the brownies are gluten-free they will sink back slightly as they cool, but this is perfectly normal for gluten-free cakes.
The 225g butter in the recipe is correct and the brownie recipe has been used by many people. However, from the description of the butter oozing out from the brownies we suspect that the butter and chocolate mixture was heated too much at the beginning of the recipe. When this happens the cocoa particles cling together and the fat in the chocolate separates out. The mixture usually turns slightly thick and will look oily. As the fat is not emulsified into the brownie batter properly, it will leak out as the brownies bake. We suggest melting the chocolate and butter over a very low heat, stirring regularly, and removing the saucepan from the heat while there are still a few lumps of unmelted chocolate left. The chocolate will continue to melt in the residual heat of the pan and doing this reduces the risk of the chocolate becoming too hot.