Add <quantity>100<unit>g</unit></quantity> of hazelnut flour, <quantity>100<unit>g</unit></quantity>of powdered sugar, and <quantity>100<unit>g</unit></quantity> of room temperature butter to a stand mixer bowl

Mix on high speed with the paddle attachment until fluffy and pale yellow

Add <quantity>2</quantity> eggs, one at a time, while mixing

Add <quantity>20<unit>g</unit></quantity> of all-purpose flour and mix until smooth

Line the sides of a <quantity>20<unit>cm</unit></quantity> diameter ring mold with parchment paper. Place it on a silicone mat and pour half of the batter. If you prefer, you can use a piping bag

Add <quantity>1<unit>tbsp</unit></quantity> of blueberries and cover with the remaining batter. Top with <quantity>1<unit>tbsp</unit></quantity> of blueberries and <quantity>1<unit>tbsp</unit></quantity> of halved hazelnuts

Bake the cake for 35m until golden brown

Let the cake cool down, unmold, and remove the parchment paper. Top with powdered sugar to taste. The blueberry hazelnut cake is ready

Enjoy! Try pairing it with vanilla cream, chantilly, or ice creams!