diff --git a/algorithm-exercises-csharp-test/src/hackerrank/warmup/BirthdayCakeCandles.Test.cs b/algorithm-exercises-csharp-test/src/hackerrank/warmup/BirthdayCakeCandles.Test.cs
new file mode 100644
index 0000000..1d1b874
--- /dev/null
+++ b/algorithm-exercises-csharp-test/src/hackerrank/warmup/BirthdayCakeCandles.Test.cs
@@ -0,0 +1,35 @@
+namespace algorithm_exercises_csharp.hackerrank;
+
+[TestClass]
+public class BirthdayCakeCandlesTest
+{
+  public class BirthdayCakeCandlesTestCase
+  {
+    public List<int> input = [];
+    public int expected = 0;
+  }
+
+  private static readonly BirthdayCakeCandlesTestCase[] tests = [
+    new() { input = [3, 2, 1, 3], expected = 2 },
+    new() { input = [1, 2, 3, 3], expected = 2 }
+  ];
+
+  [TestMethod]
+  public void testBirthdayCakeCandles()
+  {
+    int? result;
+
+    foreach (BirthdayCakeCandlesTestCase test in tests)
+    {
+      result = BirthdayCakeCandles.birthdayCakeCandles(test.input);
+      Assert.AreEqual(test.expected, result);
+    }
+  }
+
+  [TestMethod]
+  public void testMiniMaxSumEmptyInput()
+  {
+    Assert.ThrowsException<ArgumentException>(() => BirthdayCakeCandles.birthdayCakeCandles([]));
+  }
+}
+
diff --git a/algorithm-exercises-csharp/src/hackerrank/warmup/BirthdayCakeCandles.cs b/algorithm-exercises-csharp/src/hackerrank/warmup/BirthdayCakeCandles.cs
new file mode 100644
index 0000000..2b15a21
--- /dev/null
+++ b/algorithm-exercises-csharp/src/hackerrank/warmup/BirthdayCakeCandles.cs
@@ -0,0 +1,42 @@
+// @link Problem definition [[docs/hackerrank/warmup/birthday_cake_candles.md]]
+
+namespace algorithm_exercises_csharp.hackerrank;
+
+using System.Diagnostics.CodeAnalysis;
+using System.Linq.Expressions;
+
+public class BirthdayCakeCandles
+{
+  [ExcludeFromCodeCoverage]
+  protected BirthdayCakeCandles() { }
+
+  public static int birthdayCakeCandles(List<int> _arr)
+  {
+    if (_arr.Count == 0)
+    {
+      throw new ArgumentException("Parameter cannot be empty", nameof(_arr));
+    }
+
+    int counter = 0;
+    int maximum = _arr[0];
+
+    foreach (int element in _arr)
+    {
+      if (element > maximum)
+      {
+        maximum = element;
+        counter = 1;
+      }
+      else
+      {
+        if (element == maximum)
+        {
+          counter += 1;
+        }
+      }
+    }
+
+    return counter;
+  }
+
+}
diff --git a/docs/hackerrank/warmup/birthday_cake_candles.md b/docs/hackerrank/warmup/birthday_cake_candles.md
new file mode 100644
index 0000000..8e8b3ef
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+++ b/docs/hackerrank/warmup/birthday_cake_candles.md
@@ -0,0 +1,54 @@
+# [Birthday Cake Candles](https://www.hackerrank.com/challenges/birthday-cake-candles)
+
+Difficulty: #easy
+Category: #warmup
+
+You are in charge of the cake for a child's birthday.
+You have decided the cake will have one candle for each year of their total
+age. They will only be able to blow out the tallest of the candles.
+Count how many candles are tallest.
+
+## Example
+
+The maximum height candles are 4 units high.
+There are 2 of them, so return 2.
+
+## Function Description
+
+Complete the function birthdayCakeCandles in the editor below.
+birthdayCakeCandles has the following parameter(s):
+
+- int candles[n]: the candle heights
+
+## Returns
+
+- int: the number of candles that are tallest
+
+## Input Format
+
+The first line contains a single integer, n, the size of candles[].
+The second line contains  space-separated integers, where each integer i describes
+the height of candles[i].
+
+## Constraints
+
+$ 1 \leq n \leq 10^5 $
+$ 1 \leq candles[i] \leq 10^7 $
+
+## Sample Input 0
+
+```text
+4
+3 2 1 3
+```
+
+## Sample Output 0
+
+```text
+2
+```
+
+## Explanation 0
+
+Candle heights are $ [3, 2, 1, 3] $. The tallest candles are $ 3 $ units, and there
+are $ 2 $ of them.