Melt the chocolate every 30 seconds in the microwave, when it is melted, take the cones and dip them in the chocolate to form a shell around them, done that, separate
In a pan, place the condensed milk, the cream and the chocolate powder, mix on low heat until you reach the cream point.
Let the brigadeiro cool and then place it in the cones to the edge, to finish you can use sprinkles, grated coconut or whatever you prefer